I feel the same that you do in regards to the busywork. I don't ever really feel like I'm learning at school; more like I'm "learning" what's on the next test, and I don't retain it very much. It's boring a repetitve and once you learn the pattern the amount of thought put in to the work decreases by a LOT.
And the sad thing is that when teachers try to introduce discussions to into the class, most people don't even take part. They sleep.
Which of course leads to more busywork because that's all people respond to.