I would tell them that they obviously don't possess the intellectual agility to understand the abstract concepts on which the sport of boxing is built. Then I'd call them a *** and **** their mother.
"I normally don't talk with women unless I fornicate with them. So you shouldn't talk anymore, unless you want to, you know..."
I don't consider you an authority on Marco Antonio Barrera and not just because you've seen practically zero footage of the man at his peak, but primarily because you're a baby boy, too green to be taken seriously on any subject.
I had a drinking buddy, and old ass geezer who hated boxing. He was like "I don get it man, wah da point in two men beatin each udah up and den uggin each udah afta wuds?" We just laughed about it. It's cool, each to their own man, aint no need to go all Jehovah's witness on them and try to convert.