Who lauded Shaun King? He benefited from the Buccaneers tremendous defense. He was the epitome of a bus driver.
Sanchise was a cute nickname, but even he was not seen as a franchise quarterback.
RGIII was a good quarterback his rookie year. But there were still concerns about his ability to take off and run from the pocket, his reliance on his feet with such a frail body and his inability to slide.
And Tim Tebow? LOL! I was a huge Tim Tebow fan, but even I had to admit his accuracy was one of the worst in the history of starting quarterbacks.
Look, Dak may not be the next Montana, but he has more of the tangibles and, apparently, the intangibles than the guys you mentioned.