I'd like to both agree and disagree with you.
The curve for MK should have, towards where your end is, another sharp, though semi-small, increase.
MK is easily made into a good character, and perhaps even a great character. But he is not a fearsome character until you truly master him, and at that point, he is as good, if not better, than the rest of the characters(or at least that's my prediction).
I can already see a world of difference between someone who picked up MK and mastered a few small moves and someone who's been practicing with him nonstop.
With a little time and effort, he's a serviceable character, but not one to be admired.
He, like every other character, will have true potential when mastered that is just as great as any other character.