So, the conclusion is that we need active investors to eliminate arbitrage? Surely there are plenty of people who are more capable and willing to do this and are not backed by the public's pension money?

I don't understand what the author is trying to tell me about the issue. This "defense" of active investing has left me with even more reasons for why active investing is flawed and only one counter-argument that -- under scrutiny -- I cannot see holding up at all.

Am I missing something?