Easily in my top 5 pet peeves in this game is when I'm obviously not with the team, whether I'm stacking my BT in the jungle, or just plain split pushing when we have ward coverage, and then my team decides to start a fight.
I don't care if I managed to draw away their Bruiser Nidalee to stop my split push. When you 4v4 them, you're down a major damage source while they're simply down a tanky annoyance.
Obvious answer to this is, "Why were you away from the team in the first place?" And the usual response is because either we don't want to be picking fights in the first place, or maybe just exerting pressure across the entire map is the better option. A lot of variables to go into that situation.
I once had a Jax split pushing top, Taric pushing mid while me (yorick), kayle and Vayne all pushed bot. We had the biggest advantage but I guess their IQ dropped substantially mid match or something and we ended up losing since they were so stubborn. For no reason once again.
...A TV screen tied to a rock could play Half-Life...-_MechanicalFrog