It's not theory, you DO get better service when you pay for the first class ticket. I've seen it, and once or twice benefited from it. The catch is that first class ticket does cost quite a bit but that's how the world works, you get what you pay for. Only in SJW land do people get free stuff no matter what. We as a society opted for and drove the commercial aviation market toward being flying buses so it shouldn't be any surprise that customer service is on par. Virgin offers better service overall but they fly in specific limited markets where they can get the fares that pay for it.
None of that has anything to do with forcible deboarding but then most of us don't tell the airlines or Chicago security, "you'll have to carry me off". Guess what? They did.