Perhaps more importantly, corporations effectively form "unions" for wealthy people, which are an effective unit for lobbying. Jeff Bezos, for example, only owns something like 15% of Amazon...but he gets to use 100% of Amazon's resources to lobby the government and try to sell government representatives on the idea that what's good for Jeff is also good for Amazon's employees and the American public. Shift those taxes to personal income, and all of a sudden that sales pitch becomes a lot less convincing.