I think it's not the services fault that people aren't aware of the limits of encrypted services. They are not going to shut everythin' down just for a few people, if you need smth anonymous Proton is not for you.
Also, it's your task to have good opsec. If you give your iCloud email to Proton which has personal information sticked to it, your fault.
I mean, there are better options, but you can also use Proton anonymously. Just have to use it appropriately. If you use it to send your name to the FBI, there ain't nothin Proton can do about that. Same if you link a recovery email linked to a personal account.
I do not blame Proton for complying with a request - it is a completely expected action from a company. However, I would blame them for advertising that makes them seem safer than they are for people who don't know better.