Something that is not talked about which should be talked about is that it can be a challenge to transition from being a football player into real life, especially if you don't go to the NFL.
A lot of these guys have known nothing but playing football, so when they graduate, and are no longer playing football, its hard to know what to do next with your life. It can be frustrating, and some of these guys take their frustrations out on their past.
Even if you take your education seriously, and have a plan after graduation, it can still be a shock. For me, one minute I was celebrating a Rose Bowl win with my teammates, and the next minute, I was at the parking lot behind AGC Stadium, getting my luggage out of the luggage truck, and we all go our own ways. It was the weirdest feeling ever. I remember being at a restaurant with my dad the day we got back from the Rose Bowl and this feeling washed over me, like "now what?". It took me a good 2.5 years to find my way after graduating. And I am someone who was successful in class, got good grades, took my education seriously and had somewhat of a plan.
For some of these guys they didn't take education seriously, had no post college plan that didn't involve the NFL, and are stuck in neutral in their life. They have known nothing but football and for a lot of them, football was their escape and gave their life meaning. Now what? It can be frustrating, so some of these guys get upset and take out the fact that their post football life sucks on their former coaches.