Because you have to have a career before attempting to be an NFL QB. How many RB's have converted to QB???
How many NFL starting QB's did not start in HS?
How many were not recruited at all to play QB???
How many did not get a scholarship???
One year starters in college.
Kyler Murray
Cam Newton
Mark Sanchez
Mitch Trubisky
Dwayne Haskins
I am sure there are others.
Not all did great, but most had or have a decent career and not a total bust.
Ryan Tannenhill had a little over 1 year playing in college.
Kurt Warner, started 1 year at Northern Iowa. And if not for an injury to Trent Green would nat have ever had any success.
Matt Cassell never started a game in college.
Some with a little more experience in college but weren't great QB's at the time.
Tom Brady was mediocre in college, and went until the 6th round.
Brett Favre was a mediocre college QB as well
Phil Simms, Brad Johnson