I don't agree. People who got muted got muted for a good reason and it's their own mistake. It's true that the game is not playable without the ability to chat, but you still can't unmute players with a mute. They could abuse the ability to chat to break the chat rules again, and there wont be a way to stop them as a mute wont help anymore.
Even tho it's annoying for players with a mute, this is a good way to let them learn from their mistakes.