The act of genocide marginalizes the group you're "overthrowing" - or rather in order for your violent overthrow the be successful the group must be effectively marginalized
Holy shit you realize there's a difference between characterizing an ethnic group as controlling society and destroying their businesses and destroying the businesses of those that wield political power
As soon as you amass a significant majority (or vocal and motivated minority) to unite in violence against some subgroup, you are marginalizing them. They have become victims of society
Yes, the rich are some subgroup that needs protection from marginalization. They don't have disproportionate political power due to a political system set up such that those with massive amounts of wealth have immense influence on policymaking