I've seen several reviews where parents are upset by their children's behavior after watching the show, but the TV show is only supposed to be a tool for learning, parents need to be part of the process too.
If your child is behaving badly, do you act like Kai-Lan? Do you show them you care by trying to figure out what is wrong? Then teach them the right thing to do instead? If the parent isn't behaving like Kai-Lan than the kids are going to behave badly whether they watch this show or not. Kai-Lan is there to help the PARENTS teach the kids, she can't do all the work for you!
My little girl is two years old and it already works on her. The other day she was not sharing her toy and I reminded her of one of the episodes on taking turns, and she turned to her friend and said "ok, your turn". She loves the characters so that encourages her to do the right thing like they do, all she needs is a little reminder from mom!
Before you pass the blame on this show try being more involved in your kids behavior, and if you don't know how to handle your kids behavior with or without the show, then look into Applied Behavior Analysis.