I have never used a MS account for local login but it sounds to me like it just leads to people using insecure passwords for publicly reachable accounts because they don’t want to type a long password every time logging into their computer.

I guess that’s what the PIN feature is for, even though you’re Personal Identification Number can have letters…

And backdoored encryption is just as bad as unencrypted, maybe worse, since it lulls you into a false sense of security.