He wasn't a good coach for the Chiefs because he wasn't a good coach. He was dumb.
He was a different kind of dumb from Herm, though. Herm was dumb on gameday because he was a pussy soft bitch who didn't understand that putting the game in the hands of his defense meant you should probably build up a defense capable of getting those key stops when you need them. Haley was dumb on gameday because he was just stupid. It's like he possessed no cognition or rationality.
I will say, however, that if things were different and Haley could have grown from a rookie head coach at all in 2.5 years, he would represent my ideal coach. Young, hardass, no nonsense, respected by the players, and knowledgeable of Xs and Os. For some reason, however, that knowledge could never translate to the field on game day.