I think the sentiment comes from the fact that it's next to impossible to become a billionaire without actively fucking over a bunch of people along the way. You don't just "earn" a billion, you carve it out of other people's livelihoods. With the growing wealth disparity and the ostentatious displays of asset hoarding and opulence blasting the rich seem inundated with throwing in our faces, it doesn't surprise me that some people have absolutely zero sympathy for what could arguably be described as the face of the greatest threat to society.