Doom is a fucking PUNK.
Everyone talks about how horrible a villain he is, yet every damn one of his reads, at least the ones that I've seen or been suggested to see by /co/, depict him as more of a fucking antihero than an actual villain.
Joker -- Killed Jason Todd, paralyzed Barbara, killed Sarah, etc.
Magneto -- Ripped Wolverine's fucking skeleton out
Green Goblin -- Killed Gwen Stacy, all of the psychological damage to his own fucking son
Doom -- The nigga delivered Reed Richards' child.
His big "act of villainy" there was just NAMING THE GIRL. Sure, you can toss out the whole "oh well he was proving that he could do something that Richards couldn't, he could help his family when Richards could not", or the bs "Oh well he's a classy motherfucker dohoho/he's an honorable villain" crap out there, but when it comes down to it, Doom hasn't done SHIT.
That all being said, Doom crying at 9/11 wasn't any sort of break in character or anything to me. Hell, I would even go as far to say that it was entirely IN character.