My contention is that there aren't enough professional traders or hedge funds in the world for the number of them that enjoy astronomical success to be purely a result of chance.
We have clear and irrefutable evidence of firms that consistently beat the market over 10, 20 and 30 year timespans. If you want to seriously suggest that they are a normal result of statistical distribution you'll need to really quantify that. I've never seen rigorous calculations that can support that hypothesis.
Moreover, I don't understand how that argument is easier to swallow than the argument that you can reliably beat the market. What is so difficult about the idea that it is possible to reliably and legally obtain material information that the rest of the market doesn't have an edge on, or that it's possible to identify predictive patterns?