I think you're mistaking muting and blocking. Blocking is what prevents other users from interacting with them. Muting simply stops whoever is muting from seeing it, not everyone else.

So for example, if this were Twitter and you were to respond to me whilst I have you muted, I wouldn't see that response, but others would. If however I had blocked you, you would never even get the opportunity to respond in the first place. For a public space, mute is fine, and eliminates their ability to curate their responses.