Read up. It's called the Kruger-Dunning Effect. Basically, research shows that the incompetent aren't capable of accurately evaluating their own competence and tend to drastically overestimate their own skill/knowledge.

In other words, they're too dumb to know they're dumb.

Bronco haters know so little about what it takes to be a good D1 coach that they aren't in a position to accurately evaluate Bronco's performance.

http://psycnet.apa.org/?&fa=main.doiLanding&doi=10.1037/0022-3514.77.6.1121

FLAME AWAY! Kruger-Dunning will explain your reaction.