I think there is a place for the style of QB play exemplified by most Black QBs, and that's a trick-pony, once-in-a-while series to keep enemy defense's off balance. Although, it must be said, many if not most White QBs are versatile enough to change up their style as necessary, rendering Black QBs for the most part redundant.
People (and by people I mean Blacks, Jews, ****, feminists, etc.) don't want to admit it, but White QBs can for the most part do what Black QBs can to an acceptable degree, but Black QBs are simply not good enough to do the things that White QBs can. Black QBs exist simply for the sake of existing, the whole "me too, if you have it I want it waaaaa!" attitude that most people in the world who aren't White males bitch about ad nauseum.
To explain the OBVIOUS disparity between the better White QBs and those among Black QBs who are supposed to be their "signature" players (ie, RGIII, Vick, the mulatto Kaepernick, etc.), fans are told that they are not actually seeing what they are seeing, and that the superior White QBs are actually doing something wrong or obsolete.
The game can continually be nipped and tucked here and there—or reffed corruptly—to foist more Blacks into positions for which most are clearly inappropriate, but NOTHING can change the bottom line—that Whites are great all-around athletes, perfectly competitive with Blacks, and what's more, have the advantage of a superior intellect, on average.
Thus the only way to eliminate Whites from their rightful places on the field are to ignore them, throw them under the bus, or just convince people that they suck, when they don't.
This is kind of seen in the way fullbacks are a rare breed these days. The concept of a huge, bruising, Mac-truck of a player bulldozing opponents is a WHITE prototype. The Blacks who would play this position, by comparison to the Whites, are too fragile and have CRAP stamina necessary to wear defenses down.
Thus fullbacks disappeared or are rarely used, and instead midget running backs are used. Many White players have the physiology to play this position as well as Blacks, but people are inveigled with the idea that Whites are "too slow."
It's yet another case where Whites can do what Blacks can do (play runningback) but Blacks are not as good as Whites in playing fullback.
So, the game changed to cut out the fullback spot.
Maybe it's not as simple as all that, but I think a grain of truth is in there somewhere.