To deal with teammates that attack your structures?
It is about 50 times harder to stop a group of lings, or whatever from stopping teamkilling that it is to click once on each structure.
Why have you not, in 10 years, given us an option to unally these turds of life? Broodwar had it, and it was used. Sure it led to some backstabbing things, but is a hell of a lot better than allowing these pukes to ruin game after game.
And why am I being paired with them when they are in bronze and I am in platinum, when the other team has all people around the same league? Yet another failure of blizz to give a fart.