Not quite a fair assertion. It might be true that the average guy in a front-office trading desk at a bank might be more intelligent than the member you referenced or others, however, most of the times the average track record of bank traders who trade prop is lousy at best. Making markets is not a fair comparison as traders at banks take advantage of flow information and do not really make discretionary trading decision (for the most part). Example, most prop bank traders did not make a dime during the last financial crisis, they performed relatively incredibly well if they came out flat.