Where's the research to back up these claims you're making? You're throwing around numbers with nothing supporting them.
I'll do it again, just for you:
I've limited it to QBs taken from 2013 and back simply because I think it's hard to judge how successful QBs like Bortles, Mariota, Winston, Bridgewater and Carr will be at this point
QBs taken in the top five:
2012 Andrew Luck, Robert Griffin
2011 Cam Newton, Jake Locker
2010 Sam Bradford
2009 Matthew Stafford, Mark Sanchez
2008 Matt Ryan
2007 JaMarcus Russell
2006 Vince Young
2005 Alex Smith
2004 Eli Manning, Phillip Rivers
2003 Carson Palmer
2002 David Carr, Joey Harrington
2001 Michael Vick
That's 17 QBs, with Luck, Newton, Stafford, Ryan, Smith, Manning, Rivers and Palmer (tentatively) as successes, which is a success rate of less than 50 percent.
If you want to go back further than that, you can include Tim Couch, Donovan McNabb and Akili Smith from 1999 and Peyton Manning and Ryan Leaf from 1998, but it doesn't improve the percentages.
QBs taken in the 30s:
2013 Geno Smith
2011 Andy Dalton, Colin Kaepernick
2007 Kevin Kolb
2002 Patrick Ramsey
2001 Drew Brees
If you stop there, to go the same years as the top five, you've got three successes (Dalton, Kaepernick and Brees) and three failures for 50 percent.
To get a similar sample size, though, you have to go back further.
1991 Brett Favre, Browning Nagle
1989 Mike Elkins
1985 Randall Cunningham
1984 Boomer Esiason
1981 Neil Lomax
1973 Gary Huff, Ron Jaworski
1970 Dennis Shaw
1969 Terry Hanratty
1968 Gary Baban
That's 17, with Jaworski, Lomax (tentatively), Esiason, Cunningham, Favre, Brees, Dalton and Kaepernick as successes, so the overall success rate would be the same as those taken in the top five. (I think I might have included Carr and Bridgewater the first time I did this, which upped the percentage, or I might have gone further back, but I don't remember.)