I am no expert on the FR, but that article as a long list of causes, only one of which is "Increasing inequality led to more social conflict." and that's all it says about that.
Besides, it was a feudal society with nobles and peasants, with different laws attached to each. That's bound to cause resentment.
Besides, it was a feudal society with nobles and peasants, with different laws attached to each. That's bound to cause resentment.