It is about password security. Nobody should be sharing their passwords, because that is dumb and risky.
I have little sympathy for all the complainers that hate these streaming password sharing restrictions. I've never done it, and never will. I pay for all my own streaming services. They are cheap expenses, not worth compromising your accounts' security.
Cancel your shit if you don't like it, but you can't act like you have the moral high horse if you're violating the terms of service you agreed to.