Yeah, we can argue all we want, but it is only implemented as a result of users able to use free resource to mess with others by creating new account when they know that they are banned. Possible solutions:
1. Don't ban users
2. Ban users and tell them
3. Ban users and don't tell them\
4. Don't allow free accounts
Unless you know a better solution, we have to accept shadow banning as a speed bump. And like speed bumps, they unfortunately sometimes catch good-willing users, but make life better for thousands of other users.