especially considering he already said he wouldn't consider it even if he were contacted, but...
1. His teams are extremely undisciplined and don't keep their cool (see: A&M game). This is a reflection of Pelini. I would be surprised if he isn't fired from a job at some point for saying or doing something stupid.
2. The situation at Nebraska is the opposite of Michigan. If only they could find an OC. He keeps trying to get a West Coast coordinator to run a zone read offense, so they do a little of both and it has been awful. Sound familiar?
3. Taking over for Rich is very similar to taking over for Callahan. And while he was able to improve the defense rapidly, he tanked a very good offense within a couple of years (Taylor Martinez is very weak mentally. Very rarely do you see someone look so great against poor competition and so bad against good competition).