I played almost all of the famous fighting games and they all have the same problem (including SC series). Famous series cannot change even a little bit, tekken 1 and ttt2 are the same, sc1 and sc4 are the same. The same thing about them is, GAMEPLAY of course! They afraid to change because it's fans wish to stay the same. Little changes are allowed. But new SC has to different than the others. It has to be perfect and has to be the best one of the SC games. Why did they removed all of the good stuff in SC4? SC4 was like a "open beta" imo.
Final words, when you start construction of a building, you don't remove bricks from lover floors do you? It is not a Jenga game.
Edit:
I just played Tekken 6 and I noticed something. In T6, emotions and expressions are much more greater than SC4. I hope SC5 will have even more great character expressions and emotions.