First of all, students often receive extra credit for such things as wearing school colors on Spirit Day; for bringing their parents to PTA meetings; for cleaning the classroom after school; for buying items that support the school's funding; for bringing extra pencils and other supplies to class; etc., etc., etc. I've seen it done in schools where I've taught and find it way out of line.
Secondly, many teachers regularly give homework and/or special assignments simply because it's expected of them whether the student needs reinforcement or not. Special assignments that actually allow the student to demonstrate mastery of skills are welcome but too many times that's not the case. "Busy work" that is piled on pupils does little more than take up their time and rarely has any direct relevancy to educational goals.
Finally, I think that schools focusing on authentic evaluations which in reality actually prove the students' level of learning is a good thing. It's a move in the right direction toward true student accountability.
But that's just my opinion.