The whole stupid thing was just Combofiend desperately trying to cover Capcom/Marvel's asses by attempting to downplay the lack of X-Men by saying that them being gone isn't that important since their playstyles are still sort of there and it just blew up in his face because of how ludicrous that idea is in regards to a fanservice game like Marvel. It got mocked so mercilessly because it completely undermines the effort and thought put into designing characters for a fighting game by boiling it down to the most basic level and saying that's all that matters.
It's an especially stupid statement to make in regards to a fighter based around popular IPs since the major appeal for most people are the characters chosen for the roster and the movesets designed around their specific skillsets. Because of this it gives the impression that Capcom really couldn't give two shits about their IPs or Marvel's since to them they're all just movesets with famous skins overlaid on top. It also didn't help that DBFZ was rolling out it's hype train and every new character trailer showed just how much care was put in to every move pulled straight from the manga, anime or other games.