You commit to the school, not a scheme or coach. And it should be a real extenuating circumstance to be granted a waiver, not some BS excuse.
Well, you said it didn't you? What is a "real extenuating circumstance" and what is a BS excuse? There are no clear guidelines and as fans we will really never know what goes on at these schools, only what we are told.
I agree to an extent about committing to the school but the reality is the coaches make it or break it. NE is a good example of guys hitting the road when MR left and SF came in. One was pro style, the other spread. So is that fair to a kid? If coaches would have changed during Crouches time he likely would not have won the Heisman.
edit: I had a neighbor kid who also went to our church we were good friends with. He moved away and ended up being a very good athlete. He just didn't gain the weight he needed to and went to Butler CC and played DE. He was recruited and ended up at Arizona when Stoops was there. He said that was the biggest mess he had ever seen. Yelling, cussing, lack of respect, totally out of control. He got out along with several others. Sometimes what is being sold may not be what the actual product is.