Whether or not the test is football related has nothing to do with its validity.
Its meant to test general intelligence. Something that researchers
know, from literally 100 years of studying this, is that general intelligence is extremely strongly correlated with performance across a wide variety of occupations. Football included. It isn't an accident that Aaron Rodgers scored a 35, or that Tom Brady scored a 33. There's a reason Bill Belichick selected Brady in the 6th round even with his
combine performance and obvious lack of athleticism
- such a high level of intelligence (~127 IQ when converted from the Wonderlic scoring system) coupled with his performance at Michigan made him an absolute steal.
Just to let you know, a 127 IQ puts Brady in the top 4.5% of the US population in terms of intelligence. And Rodgers' 130 IQ puts him in the top 3%.
Are there outliers? Absolutely. There are people with 80 IQs who are able to make billions of dollars. Dan Marino killed it for
years in the league with a low Wonderlic score.
But on average, across populations, a low IQ indicates a lower probability of success in complex, rapidly-changing situations. Think of it as a measurement of mental horsepower.
All things considered, I would want my QB to have as much mental horsepower at his disposal as possible - it would give me far greater confidence in his ability to handle complex and rapidly-changing situations, and would give me more flexibility in the type of offense I designed for him to run.