His last two fights have been against huge draws who are adored by the mainstream. He didn't have to think about bringing that crowd in. Now he's on his own and has to appeal to a broader range of buyers who have never heard of Marquez.
This is another reason. Much like Hoya had to go on and on about how much of a threat Pac was when the whole boxing community was in an uproar over his pick for the fight. But yeah, he can't belittle MArquez when everyone is doing it for him.