I don't know that "Braves fans" are—I've just personally always been a bit skeptical of Peraza as a prospect, at least as far as offense is concerned. Empty averages scare me, especially from up-and-comers. So, yea, there is at least one person (me) "wondering if he can be a good major-league regular in the future", because a .296/.335/.384 (for instance) is a difficult line to carry at 2B if your team is offensively deficient at SS, C, and 3B as well (not to mention carrying a power-sapped RF).
But the issue then is the other positions. That line would be fantastic, especially when combined with good defense and great speed, at 2B. You don't toss aside a good 2B because you don't have power elsewhere. You find power at those spots, where it's much easier to do.
We wouldn't get rid of Simmons because our C and 3B can't hit. Because Simmons is a great SS. If Peraza is a good 2B, that's all that matters from his standpoint.