Who gives a shit? Many people, obviously. And for many different reasons.
Here are two simple reasons why I care:
The CEO stating support for Trump suggests that either their values align with Trump, or that they are bought / corrupted. Either way, I see that as a sign that Proton is likely to make moves that I disagree with. People's values guide their actions, and this CEO is showing values that I disagree with. So I can no longer trust their actions.
Even if the Proton products are perfect, if the CEO openly supports Trump then we get a 'Nazi bar' type effect. Whenever I share my proton email address with someone, it will signal to them that I frequent the Nazi bar. ... I don't want that association.
The moment proton makes any moves against privacy I will leave them.
But just because the CEO doesn't have the same values it seems silly to me to migrate.
And if someone calls you a nazi for merely using a service which happens to be developed by a conservative, you're not the problem.
Whenever I share my proton email address with someone, it will signal to them that I frequent the Nazi bar
No. Most people won't ever hear this, the media don't really give a fuck. Google donated directly to Trump's inauguration fund, so by your logic everyone using Gmail would also be associated with this Trump Nazi bullshit. Fuck Trump, but your point doesn't really make sense here.