nauthiz:
it is easy enough to just ignore whether something is red
Easy isn't mutually exclusive with 'not annoying'. I find it incredibly easy to insult others, but I wouldn't want to provoke suicide.
Players are supposed to respect GMs enough not to ignore threads, and if there's an option to ignore them all, that eliminates the need for the player to respect the GM and tell them they don't want to continue the game.
In any case, you also mentioned how that level of granularity is prohibitive, but I don't particularly understand, prohibitive to what?