What downsides?
I can’t think of many, except the taxation aspect. And maybe broker’s fees for dividend processing and currency conversion, if applicable,
On the other hand:
…and some may not know any better than to distribute (part of) of that money to shareholders.
Which (and I remember we have briefly touched upon that with Cortana a while ago) does not have to be a bad sign. Dividend-paying businesses are mostly healthily profitable. And I’d rather have them distribute some of their earnings to me as a shareholder than the company forcedly trying to “reinvest” them into something they aren’t really competent in.
In a way, dividends can make (some) companies operate and allocate their capital more efficiently.