I think it's important to distinguish "platform compatibility" from the kinds of feature requests he's talking about, because I don't think the take home lesson is necessarily "cater to some minorities' requests".

Adding Mac support didn't make DropBox any more complicated for the end user -- there were no new corner cases or potential conflict scenarios, no new steps in the setup, no additional configuration complexity, basically no cost at all in terms of end-user mental load in order to extend their product beyond the Windows platform and reach some important taste-makers.

This is distinct from the end user confusion created by adding, say, multiple folder support or any of the other complex features and configuration options that users will clamour for. When you don't carefully curate those kinds of features, you end up sticking your users in tyranny-of-choice territory in a way that simply broadening your platform support doesn't.