Maybe it's just my area, but Arcana Heart 3 seems more popular than any iteration of BlazBlue at this point.
When it comes to the selection, there were really only 3 variable slots. You knew SSF4AE2012, UMvC3 and SFxT were going to be there.
As much as I don't care for it, they had to have Mortal Kombat there. It's a smash hit with American audiences and huge with the casual crowd, as evidenced by all the 'Fighter of the Year' awards it won.
EVO seems to always have a Namco fighter, and I'd say much better that it be SCV than the snooze-fest that was Tekken 6 last year. When the most entertaining thing about your tournament is Aris + Kayo Police... yeah. That means something.
So, there was really only one slot left to give, and considering how amazing a reception KOFXIII has been getting with the hardcore fighting game fans, there really wasn't a choice.
There's always side tournaments.