Just to add some numbers to this............. in the last 10 drafts (Not including the 2015 one since Winston and Mariota were rookies), 27 QBs have been taken in the first round.
10 success hit - Rodgers, A. Smith, Cutler, Ryan, Flacco, Stafford, Newton, Luck, Bortles, Bridgewater.
17 non success hits - J. Campbell, V. Young, Lienart, Russell, Quinn, Sanchez, Freeman, Bradford, Tebow, Locker, Gabbert, Ponder, RG3, Tannehill, Weeden, Manuel, Manziel.
Now one could argue someone like Tannehill should be considered a draft hit but you could then also argue that a guy like Cutler shouldn't be considered a draft hit.
I'll repost something I did in another thread here:
http://www.nfl.com/draft/history/fulldraft?type=position
With the talk about drafting a QB in the first round vs later on, I was curious about the odds of drafting a decent QB in various rounds. Using the above linked reference, I looked at the last 20 years of QBs drafted and tried to determine IMO which QBs were Decent and which were Elite and the % of those in each round drafted. I only used drafted QBs not FA so Romo and Kurt Warner could be added to this to argue for drafting lower.
Now, opinions vary, and some QBs I think were decent others might not or vice versa. But here's my analysis:
1st round draft picks (QBs)
Total = 50
Decent/Elite = 22 ( 44.0% )
Elite Only = 11 ( 22.0% )
2nd round draft picks
Total = 24
Decent/Elite = 5 ( 20.8% )
Elite Only = 1 ( 4.2% )
3rd round draft picks
Total = 24
Decent/Elite = 2 ( 8.3% )
Elite Only = 1 ( 4.2% )
4thd round draft picks
Total = 28
Decent/Elite = 2 ( 7.1% )
Elite Only = 0 ( 0.0% )
5th round draft picks
Total = 30
Decent/Elite = 0 ( 0.0% )
Elite Only = 0 ( 0.0% )
6th round draft picks
Total = 41
Decent/Elite = 4 ( 9.8% )
Elite Only = 1 ( 2.4% )
7th round draft picks
Total = 41
Decent/Elite = 0 ( 0.0% )
Elite Only = 0 ( 0.0% )
Elites = McNair, Manning, P., McNabb (I know he choked a lot but still), Brady, Vick (for his first few years at any rate), Brees, Palmer, Manning, E. (He has 2 rings so I put him here but debatable), Rivers, Rothlisberger, Rodgers, Newton, Wilson, and Luck (still has a lot to prove though-based on potential)
Decents = Collins, Stewart, Johnson,Plummer, Hasselbeck, Culpepper, Pennington, Bulger, Schaub, Alex Smith, Cutler, Ryan, Flacco, Stafford, Dalton, Taylor (gave him benefit of the doubt, will probably suck), Tannehill, Cousins, Bortles, Bridgewater, Carr.
Like I said opinions will differ on these, but it does show some trends.
If you want to get a decent QB, 1st round is your best bet by far. If not then, you at least have a shooters chance in the 2nd round. All other rounds and you have to win the lottery. To get an elite QB, your only realistic shot is the first round. Otherwise you will undoubtfully fail unless you are EXTREMELY lucky.
If we got a shot at drafting a first round talent at QB, we have to try IMO. I don't like the odds if we try and get cute.