So this guy got butthurt because a utopian kingdom treats commoners with a bit of dignity to keep them blindly loving the nobility and his elitist views were seen as a hindrance to that edict.
And all that happened to him for that was that he was simply fired. They didn't banish him, strip his nobility, rob him of his land or wealth. Simply let go from that position.
So because he was fired, probably with all sorts of severance, he's going to not only destroy the school but the very kingdom that has raised his family to its elevation. All because commoners... get to go to school...
I'm gonna believe he's being controlled by a higher evil. Because that has to be one of the dumbest reasons for grand treason I've ever had the displeasure of reading.