tl;dr
So essentially, the short version regarding the UMvC3 trolling is, it's really not trolling and don't sweat the small stuff like that. Cameos are in for fun, not douchebaggery, and there's really no malice behind it.
Pretty much. Like you've said, Capcom are not doing it to make MM fans angry, MM fans are doing that to themselves, HOWEVER, it IS Capcom's fault entirely that that happens because of how they've handled the situation.
Also, on the whole $40 expansion thing and Capcom having no interest in using its DLC, personally I don't mind that much. The way I see it, those are $20 less that I have to pay for all characters (if they were going to keep their prices the same it'd be 5*12=$60 for the characters alone), plus it comes with more stages (although as good as they look, none of them are truly new), and system and balance changes. It's also way more convenient for gatherings/tournaments, because if Jill/Shuma were any indication, chances are I wouldn't be able to play with half the new characters every time I go to my weekly tourney -.-
Now, whether all that stuff should've been in the original version in the first place is another argument. Still, I'm sure you know how companies work; even if the ones making the game would've wanted that, the guys at the top of the company make it impossible.