All Kraven really wanted to do when he first fought Spider-Man was to prove he was the best hunter/tracker/killer of things that go squeek ever. So he planned to take out Spider-Man, since at the time he was one of the most powerful of heroes that a normal human could fight. So half the time in a fight, Spider-man would try to crush his ego, in hopes that this crazy nut would stop trying to kill him after Spidey showed there was no way for Kraven to win.
Plus, let Pete have a little damn ego. He's trying to get some catgirl action going.