That guy clearly never heard about the Pareto Principle.
E: fuck yeah, successfully triggered all the hexbear tankies. As fun as poking a wasp nest with a long stick. If only there was an online tankie bug spray equivalent...
If 20% of people own 80% of the land or wealth or whatever in a capitalist country then all that shows is that capitalism produces Pareto distributions. That does not mean Pareto distributions are some universal law of nature nor does it mean that non-capitalist systems are impossible.
The one that stated that 80% of the land in italy was owned by 20% of the people? I think they did hear about it and did apply it to Cuba but I might be wrong there.
The Pareto principle is an economics idea - something is considered Pareto efficient if you can make someone better off without making someone else worse off, and you are at a Pareto optimum when you can't make anyone better off without making someone worse off. Of course, because "better off" and "worse off" are entirely up for interpretation, people argue that taxing the rich to improve the lives of the poor is not Pareto efficient because you're worse off if you have less money regardless of how much money you have left. So the only Pareto efficient solution is to grow the economy until all the poor people make enough money.
It's a "rule" invented by a proto-fascist about how 80% of things are caused by 20% of other things. It works if you assume that 70% = 80% or that 15% = 20%. And since you can control both variables you can just make everything fit anyway.
edit (not really, it's a fake edit): I should have read to the end before commenting lol. In UX
The Pareto Principle is a bullshit theory where a crank saw a handful of statistics were similar and thus decided it was a natural law. The only reason it's still considered seriously is because economics is to mathematics what astrology is to physics.