If someone irritates me in real life, am I expected to invite that person along every time I go out with my friends? The answer is no, I don't, and depending on why I exclude that person affects others' perception of me.
If I exclude that person because of their political beliefs, then most others will perceive me negatively and exclude me from their social gatherings. I would become socially isolated. If I exclude that person because they're rude to everyone, then others won't care that I exclude that person from my social circle because they're excluding that person as well. This is basic human interaction.
Mute is no different. Someone has decided that they don't like you and don't want you participating in their social gatherings. It's no different than not being invited to a party. Kleinbl00 is in no way excluding you from participating on Hubski, nor is he preventing you from expressing your political/religious/social beliefs. But he has decided that you aren't invited to his discussions.
Mute isn't evil, it just makes Hubski similar to real life.