I do agree -- it was just the only semi-reasonable argument I could think of. It probably made some amount of sense before password managers were really a common thing, and you wanted to be sure that users didn't typo a new password and lock themselves out of accounts.
It never makes sense. I know how to use dev tools to remove your no paste option, my mother doesn't. She will simply use Password1!. That's how you get weak passwords. Don't make it difficult using strong passwords.
