Why?
As the saying goes, the people need bread and circuses. Delve too deeply and you risk another French Revolution. And right now, a lot of people in supposedly-rich Western countries are having their basic existance threatened by the greed of the elite.
Feudalism only works when you give back enough power and resources to the layers below you. The king depends on his vassals to provide money and military services. Try to act like a tyrant, and you end up being forced to sign the Magna Carta.
We've already seen a healthcare CEO being executed in broad daylight. If wealth inequality continues to worsen, do you really believe that'll be the last one?