That's odd, because my AP experience was exactly the opposite. While I did have more homework in AP Literature, the homework was meaningful, personal, and founded on the cumulative knowledge attained over the course. On the other hand, in my AP Statistics class, the homework hardly counted at all while the emphasis was on the tests (which I feel is appropriate for the subject). In my ordinary classes the homework was boring, redundant and even comical at times.

I think the general trend of AP classes is to focus on getting people passing grades on the exam, and this hurts the ability of the class to explore into other topics, or doing things that would not contribute greatly to that specific goal. English essays would be formulaic, and my history class was constant timed practice exams and formulaic essay writing. If I remember correctly, some of my teachers complained about not being able to explore off-topic.

I should note that lately I've discovered that my experience in AP Lit was highly unconventional.