Actually I don’t think it would be an issue, iirc for the facilitated naturalization the canton does the interview on behalf of bund and bund wouldn’t care.
It’s highly canton/Gemeinde dependant, eg Zürich has a standardized test with about 300 questions where you need to score at least (iirc) 70%.
In Zürich you also typically don’t “hard fail”, if there’s issue they’ll pause the application while you improve (hence the extremely low fail rate).
Italian and French friends of mine in BS thought they could skip learning German and found out the opposite, neither Italian or French cut it for applying for citizenship in their Gemeinde, apparently.
On a personal level, I looked into it but doubt I’ll ever bother to get it given I don’t plan to stay here long term. I want my kids to get it for if/when the world goes to shit, and to have the option but for me it doesn’t provide any benefits I’d care about. I’d live in the UK or Greece, nowhere else is in any way interesting for me, maybe Serbia because we have family/property.
Formally you may have a point, but now reality: you are being interviewed by somebody who’s main language (in this case) is German. In fact, they’d prefer speaking Schwyzer Deutsch… and in my case asked walking up the stairs to the interview room whether that was OK (which was already a small test around integration, just like everything from the moment I walked into the building). I politiely requested we speak Hoch Deutsch because I can more easily express myself that way and the interviewer obliged. I strongly suspect if I had said that I preferred to speak French, Italian or Ratoromanisch that it would not have been appreciated (assuming the interviewer would have even been capable of conducting the interview in those languages). There’s a human aspect in these interviews and you want to be the “no hassle” person to maximize your chance of success because they can make the questions very difficult if you annoy them or - in my case - I had very good rapport with the person and on the few cases where I got stuck she actually helped me along.
Good luck though if you’re going to try your integration interview in a different language, do let us know how it went! 
Were they on the facilitated path? (They are very different).
I understand your point. However, if someone is already proficient in Italian, French, and English, it feels somewhat unfair to be denied nationality solely because they don’t speak German.
It would be similar to requiring someone to speak Italian when applying for citizenship in Ticino, even though Italian is spoken by less than 10% of the population.
Didn’t have the chance to try it since it got full naturalization 
I probably would have tried it with facilitated tho, just to see what happens (I’ve definitely read/heard stories where people requested a translator so I don’t think it would be a blocker)
I don’t know, they are here for ~15 years with C permits but have no other connection to CH as far as I know, so that’d the be standard naturalization procedure.
I don’t think the issue is fair/unfair but rather that it’s awfully difficult to be integrated when you don’t speak the language where you live and all the social/professional consequences which come with that. Even more so as you’d have had years to learn the language and apparently did not make an effort.
I only partially agree with that view. For example, someone might live in Bern but work in Lausanne, with most of their friends, colleagues, and daily activities based there. In such a case, the language they use to integrate socially and professionally may not be the one spoken in their canton of residence.
I think it would be more fair to require the knowledge of at least one national language.
You can disagree and in fact it could very well be that requiring knowledge of one national language is the official requirement… but you also have to face reality.
Again, fair / legal is not what I am concerned about, I just wanted to pass the interview.
Keep in mind, 2/3 of the country is German speaking.
Also bear in mind, that if you are getting citizenship you’d also be able to vote on local topics which in the case of Bern they would prefer you to be integrated in Bern than Lausanne.
Now yes, you could also easily live in Lausanne, get citizenship there and the month after move to Bern and you would still vote on Bern even though you might have no “close” connection to it apart from a bed to sleep. This invalidates the previous argument to most extent, but the person interviewing might not see it that way.
Btw, at least in ZH you indeed have to provide some kind of German certificate (unless your mothertongue is German and some other exceptions):
I don’t know, I see it a bit as backward thinking.
I have lived in Belgium, which has three official languages (French, Dutch and German). To get nationality, it is sufficient to have good knowledge of English. I think that is another extreme, because I feel you should speak at least one national language. But whatever, rules are rules
I mean, being outside one’s own country is pretty cancerous, even if one doesn’t like their own country 
Switzerland is different, cantons still have quite a bit of independence and you’re getting citizenship at all 3 levels.
Speaking English well does not display effective integration in Switzerland and your local community.
The Swiss have a good country, they’d like to keep it that way, and at the same time they have the door (somewhat) open for immigrants while being clear that you need to adjust. Can’t blame them. In fact, it makes a lot of sense precisely because of the diversity in Switzerland that you need to show you are well integrated.
I am definitely in favor of requiring proficiency in at least one national language. When dealing with official documents or administrative procedures, you can always request the paperwork in one of the official languages.
That in principle works when dealing with (local) government, but not in the rest of society and that’s what the integration assessment primarily focusses on.
It’s not just that Switzerland has multiple national languages, these languages are (largely) split along geographical (cantonal) borders. Don’t know about where you live, but in the town/canton I live I’d not be able to effectively function if I only spoke Italian or French (never mind Retroromansh!).
By the way, as per SEM: the language requirement is “Knowledge of the national language spoken at the place of residence” - this is direct from a SEM document, no interpretation… although the point comes from cantonal practice, not from a standardized federal legal provision
Cantonal implementations reflect this principle. For example, in the Kanton Bern naturalization procedure, the applicant must have knowledge of the “language of the administrative district in which they live.”
I think it’s an uphill battle to try to get a Swiss passport when living in a Canton where you do not speak the local language. If you think it’s unfair, become a Swiss citizen and organize a referendum to change it!
Indeed this is the first requirement for integration in Ticino for ordinary naturalization.
I am a native Italian speaker and “proficient” in French and English. I live in SO and have always managed well using English. I am also actively involved in sport clubs and have a group of international friends, so I consider myself well integrated, even though I don’t yet speak the local language.
I am currently studying German because I believe it is polite and respectful to learn the local language, and of course, learning a new language is always valuable. However, my point is that knowing the local language does not necessarily equate to being well integrated. For example, I lived in Belgium for six years and never felt the need to learn the local language (Dutch) to feel fully part of the community.
I believe that when living abroad, it is essential to adapt to the local culture and traditions and to show respect for them. This includes not only language but also religion, social norms, and everyday practices, for instance. However, these aspects are difficult to quantify, which is why language proficiency is often used as a proxy for integration. From my point of view, this is not necessarily correct. For example, I have had Muslim friends who learned Dutch very well, yet they were not integrated at all into the local community despite their language proficiency.
Nevertheless, rules are rules, and I respect them
You may be exceptional then. I imagine (almost) everybody considers themselves to be well integrated. The SEM/Canton will say: you can prove that by (among others) speaking the local language.
They may go overboard… I recall a story (not sure if true) about a German PhD in German Literature having to still go through a German language test in Switzerland to prove her German speaking capability
I’ve lived in close to 10 countries - speaking the local language to a reasonable degree in my mind is an essential condition to integrating well (especially in a smaller town).