Whats up with people and mark me missing keybinds

If, for example, I were to fake the use of my killbind, I really wouldn't get much off of it, either as a T or as an inno trying to RDM. I don't get some "sneak" buff, and anyone who actually does mark me as missing will no that it's false the second they see me; if anything, they'll be more wary. Since the rules won't let you kill based on logic that is not 100%, doing so shouldn't (in a perfect world) lead to any negative consequences.