In the whole Proton situation, there are a lot of mixed equities and real problems surfacing, but not all of them are appropriately ascribed to Proton.

Let's put aside for the moment that the FBI sucks. They do! Under the US MLAT with Switzerland, is it Proton's role to deny the request from the US government?

Is it not; it is the Swiss government's role to do so if they wish. If they do so, they endanger a treaty that has been in place since 1977, while also signaling to other countries with similar agreements that their word is mud—or at best, contingent on them liking the current government of the ally country.

Maybe not an awesome tradeoff to stick it to the Feebs.

And Proton, like them or not, has been clear about their position on honoring Swiss law from the jump. And should they leave Switzerland for another EU country, it will be that state's laws they abide by.

You may contend that Proton should deny lawful (note: not necessarily ethical) requests from their government to protect their users. That's a position you can take, but I don't believe it has ever been Proton's. Their primary privacy offer is end-to-end encryption between email addresses that support it, and on-disk encryption of your data, along with a VPN. They make anonymous accounts possible, but do not guarantee any data you give them will be withheld from lawful requests from Swiss authorities, which is what happened here.