Everybody tends to put that certain point above where they are at. I realize, as limited to a US discussion, it is easy to say Bezos and Gates are rich, I am not. But if this was expanded, simply as a thought experiment, to the entire world would you be fine classified as a "fat cat"?
Assuming (perhaps incorrectly) you are in the US, you are also reading Hacker News, so you are probably the top 1% of the worlds wealthiest. Again, just a thought experiment, but would you be fine with your government saying that as a 1 percenter in world wealth you can no longer earn anymore, you have hit that certain point, are a fat cat and can grow no more wealth, under threat of criminal law?