Certainly he does have a vested interest. Not the end all-be-all, but he does cite the board of governors and hendershott-riodan as evidence it reduces volatility, some indirect evidence in the short selling ban, the history of QQQ as evidence of lowering cost, tightening spreads.

The 'fair value' he's talking about us just the supply-meets-demand of that stock for that particular moment-- that moment could definitely take place in a larger bubble of that security. The mini-bubble within high freq trading he refutes by reasoning only ("another hft would detect this"), so I think a more concrete example would've been more convincing. As with all bubbles the question is how far out of line can the price get, and how quickly will the price be brought back to reality