If I work and pay taxes and and save what's left, I want to leave it to my kids. Nothing wrong with that except jealousy. Inherited stock shares do no harm to the public, and inherited wealth that is not productively invested tends to vanish in a few generations.
Illegal acts should be punished. Kleptocracy should arguably be illegal.
Creating general wealth needs big organizations, and someone needs to create and manage them. Governments are terrible at managing productivity. Communes and collective farms and factories have never worked; those were recipes for starvation.
The greedy railroad barrons created enormous wealth (ie productivity) for the entire population. The basis of the transcontinental railroad was clearly kleptocracy.
So did Ford and Edison create great public wealth, the greedy rich bastards.
The unions claim that they invented the weekend. They are wrong.