It seems more of an issue when Communication is KEY in a gamemode like TTT.
If someone starts micspamming, but only 2 / 9 players Muted said micspammer (You and one other person who is already dead) and you SEE the traitor, you're yelling as loud as you can over the mic "ITS ______ ITS ______ HES SHOOTING ME WITH A TMP, FUCKING HELP--"
And nobody would know any better cause everyone in the server is a fucking moron and either likes to have their speakers blow out, or doesn't know how to mute.
But I also agree a votemute would be REALLY helpful. Some people don't play music at all, and use HLSS for soundboards and such.
The game is really meant to be fun and not annoying. A Vote mute would be veeeeeeeeeeerrrrrryyyyyyy noic.