I didn't know that many people disliked it
. I haven't seen it in a long time but I remember enjoying it when it was running.
It's very underrated. I think one of the reasons why people didn't like it is because the title is a pun on "kick butt", so it probably led people to think it was just another Fanboy and Chumchum. Kick Buttowski wasn't perfect, but it was still a solid show in my opinion, and it should have gotten more than 2 seasons.
It was funny (even the gross-out jokes were well done!), it had a lot of likable characters (though it did have quite a few unlikable characters too) - Hush and Razz being my personal favorites, and it had some pretty fluid animation, especially on those action sequences with Kick performing crazy stunts.
And how many other kid cartoons have you seen with primarily hard rock soundtracks? The theme song even sounds like an ACDC song.