My stance on Proton is my stance on GrapheneOS: just because the creator is bad doesn't mean the software is bad. As long as the software is better compared to the alternatives then I seen no reason to stop using it.
Note: better can mean more privacy-friendly, cost-friendly, sustainable, nice to use, open, etc.
Oddly enough, I found the opposite to be true with companies like Nestle: the news of them killing children makes me dislike their chocolates.
This reddit thread has a nice summary