There's no reason to play this game really, I doesn't bring anything new, or at least anything every remotely interesting to the fighting genre.
You've seen it all and done it all before in Capcom games, only much better and not nearly as rushed (which is exactly how this game feels.)
I'm sure people will buy and play it, but I honestly don't see the point.
It's a novel idea to try and combine all of Capcom's previous fighting incarnations into one game, but it's not something that's going to work out well when you put little-to-no effort into making the game, which sadly, is the case with CFJ. I'm not bashing this game for the sake of bashing it, because I really wanted to like this game, but it's just sad to see a company, who produced such a high-quality piece of material like Third Strike, follow-up with something like this; it's quite disheartening really.
First it was SNK and now it's Capcom.
At the very least, now SNK [SNKP] has moved to the Atomiswave, and seems to be putting a bit more effort into things, but now it's looking like it's Capcom's turn to take the plunge into fighting mediocrity.