Pinnick honors Bryce Young and Kyler Murray are hardly doing "just fine" in the NFL, unless you mean they got drafted highly and got paid. Young is 23rd in QB rating out of 33 qualified QBs. Murray, if he qualified, would be 20th. Dillon Gabriel is 31st. Tua is 26th. I mean, credit to them for making it but their lives would be a lot easier if they were 6'-3".
We've got decades of examples that it is an issue being under 6'-0" if you want to play QB at the NFL level. This is not my narrative. This is how the NFL has operated. Look at the top 10 guys this year in QB rating. Only 1 of them is listed at 6'-1" or shorter and that's Jalen Hurts, who is listed at 6'-1" and is one of the most mobile QBs in the league. All NFL teams care about is what helps them win and they all prefer taller QB's. What does that tell you?
For the last time. that does not mean it's impossible for a 5'-11" QB to make it in the NFL. Drew Brees is a HOFer. Russell Wilson has had a great career. I'm sure there are others. It just makes it a lot harder to be successful if you're 5'-11" as opposed to being 6'-3".