Comment by sparkie

Well, you can have certain differences of opinion as long as they're "acceptable" opinions. Academia ousts those who don't fit into its culture. Tenure is the only way you can express your real opinion without reprisal, though you may still be socially outcast for having the "wrong" opinion - and those who make it this far are predominantly products of that same culture - their opinions align with their peers on what is deemed acceptable. The anointed.