He's not wrong but it would suck if every guy at every weight class was the same size. Part of the sport is seeing the 20 lb smaller, lighter, but faster guy take on the 20 lb heavier, bigger guy. It's an archetype matchup and it would suck to see that element of the martial arts taken away from us from all but heavyweight or the odd super fight.
Grey Maynarrd vs Frankie Edgar, Edgar vs Penn, Sherk vs Hughes, GSP vs Penn, Sakuraba's entire career, imagine if these matchups never happened. Something amazing about the sport would be taken away from us.