Hatake Kakashi was a shinobi, and as a shinobi, the only people who could give him orders were his military superiors. The idea that a Council made up of civilians and peers was under the impression they could give him orders...displeased him. Or: He was ordered to pass Team 7. He was fine with that, until they actually passed.

Set around ch.307. Spoilers. Trying to fix a three man team has its own quirks for Sakura, especially when there are four people involved.