We want to first clarify that Proton did not provide any information to the FBI, the information was obtained from the Swiss justice department via MLAT. Proton only provides the limited information that we have when issued with a legally binding order from Swiss authorities, which can only happen after all Swiss legal checks are passed. This is an important distinction because Proton operates exclusively under Swiss law
I don't use Proton products at all (not for any idealist reasons), but I don't really think this can be much of a condemnation of the company. I don't know what else you can expect them to do in this case.
edit: That said, the real takeaway is that if you want to remain anonymous to a service that can be compelled to hand over data about you (read: more or less any service you might want to use), you should not pay with a credit card linked to your actual name, you should not access it from your home IP address, and you should not use it in any way that links it to your real self.
Proton is security focused, but even they are bound by the laws of the country they operate in. Use TOR, use E2EE, pay with cryptocurrency, maintain hermetic separation between your anonymous and public selves, etc.