Well, whether it makes a big difference or not, there could just be wink-wink nod say-no-more between teams. And the refs won’t get interested unless someone complains. If every quarterback has their own sometimes wildly different preference, it could just be every team is scared to ask the refs to check because they know the other team will ask in retaliation back at them. That happens in baseball when someone complains to an ump about loaded or scuffed balls, sometimes they know something is up but they probably have a pitcher on their team that does the same thing.
It would be interesting to know exactly how this came to the attention to the refs.
Freegards
Well, whether it makes a big difference or not, there could just be wink-wink nod say-no-more between teams.
Or a “good enough” standard which doesn’t extend to an industrial QA level of interest. Why bother to cut logs to the micron for shipping?
In this case, the balls need to be inflated enough to be solid, and not so overinflated that they will be permenantly deformed, fail, or not be cushioned if someone falls on it. 12.5-13.5 PSI is really just the manufacturing standards of the bladder inside the football. It’s still perfectly functional at 10.