This was exactly the point of the outrage, servers ought to be able to opt out of this system but they can't. There are mods [1] that server admins can use to remove the chat message signatures, players are powerless if they strip the signature that certified ever message they send, vanilla servers will block them by default and prevent them from joining.

It is true however that there wasn't really the wave of false positive bans happening that the community was expecting. At least as far as I'm aware.

[1] https://www.curseforge.com/minecraft/mc-mods/no-chat-reports