Not necessarily. A pair of kings isn't necessarily worth putting all your chips in the middle pre-flop unless you are short stacked, particularly when you raised and then were re-raised. It depends a few things, not the least of which is how the player had been playing up until that point. Call the bet and see a flop. Granted, given the flop that occurred the money would likely be all in afterwards but he got aggravated and just went all in on a whim.