The question is, did MK improve when it turned 3D? I think it's pretty fair to say..NO. Will it improve eventually if they keep it 3D? Well ... I don't believe so. Yes, I'm an old school MK fan..but .. yes..I'm openminded for changes. The fact that MK vs. DC went a little bit back to 2D is a sign that the team realized that it didn't work, but were too afraid to make it fully 2D or like SF4, which I prefere. The first MK's were an succes, not only because of the gore, story, etc. But also because of the gameplay. If you make it 3D, make sure that the basics of the game can move along with this change. But it can't, unless you'll make it another Tekken, DOA, etc.
Gamers (that are not MK fans) still play UMK or MK II. Some of them didn't even know that there was a Deception or Armagaedon. It's nice that the games sales were good, but if I'm a creator ..I rather make a game that sells less and is remembered & acknowledged as a great game. How many gamers will play MKDA or Deception after 15-20 years like MKII or UMK3? Exactly.
The team need to make a quality game and I think going back to 2D is the first step. Everything else (sales) will follow.
EDIT: it's the second step, getting Tobias back is the first.