This is truly a wild analysis. It's entirely plausible that Black rock owns the longs and Citadel owns the shorts and that they collaborate. But just the circular ownership leading to total dominance of the market by a few hundred people is enough to make this worth reading.
I think the author's politics are liberal and the author's beliefs about history and politics are the result of propaganda. But the analysis of ownership itself is the thing I found worth examining and considering.