Anon is a privilege, not a right -
Just as it says - Anon is a privilege, not a right. You don't have to keep anon turned on if people in your inbox are abusing this privilege. Anon should be for sending love and encouragement, or for asking fun questions.
If you don't like someone, you don't have to follow them, or interact with them. You can unfollow, or block, or blacklist their URL. Anon should not be used to spread hate and discouragement in the roleplay community. If you wouldn't say it with your name attached, you probably shouldn't be saying it at all. It's like putting on a ski mask, and showing up on someone's doorstep to shout obscenities in their face. This is not what anon should be.
If you don't like someone - it is NOT your job to tell them why. And if someone asks for criticism, anon is not your free pass to be a jerk. If you can't be constructive with your critique, then keep it to yourself. You aren't doing anyone any favors abusing the anon button to shout in people's faces. You're just part of the problem.