Vick never got injured down field. All his injuries came by bad OL play in the back field. Culpepper was not a bust. He was an elite thrower of the football. Who else? What other dual threat QBs in this long NFL history who were bust?
Well, in this past 5 years alone I would say every single pocket passer were total bust. From #1 picks like palmer, linart, quinn to weedens, grossmans, clausens. Seriously, any successful pocket passers the last 5 years. I can't name one. While you're referring to 10 year vets like culpepper & vick. Is that all you got?
Actually Vick's OL were pretty good the year Ray Lewis broke his leg. But then regardless of whether his line was good or bad, Vick's finished...what? Two seasons without missing a game? Lousy example to use as a dual threat since he was never that great a passer.
And Culpepper? Seriously? Culpepper became utter crap the moment he lost Randy Moss as a receiver. He was the worst quarterback in the league well before Chris Gamble took his knee out.
As to the last five years, there have been precious few great QBs of any stripe that have come out, but the notion that only the pocket passers have been busts is dumb. This year's guys are too young to judge just yet, but guys like Andy Dalton, Christian Ponder and Matt Stafford are all pretty decent. Heck, even T J Yates had good moments. Oh, and there's also this guy who's playing in the Super Bowl next week.. Fellow by the name of Flacco. He was drafted in 2008.
Do yourself a favor and give up on this idea that only black QBs and read option guys are dual threats. Steve Young was one of the best ever and great at both areas. For that matter, very few pocket passers are all that immobile (Dan Marino was an exception, not a norm). They just aren't great running threats. And yet somehow, guys like Brees, Manning and Brady still manage some level of success even without that talent. And let's not forget a guy like Aaron Rodgers, someone who's perfectly capable of running but doesn't need to because he's extremely effective as a passer.
Bottom Line: Passing is still the skill quarterbacks need most to succeed. Running is a nice thing to have, but not necessary to become a winner.
And that's not likely to change anytime soon.