It's not the QB's that's the issue here. THis is similar to the spygate thing. There are things that happen in football, and rules are pushed, but the Patriots clearly go a step beyond with pushing the limits, and they get caught.
When the balls are apparently as deflated as they were, across the board, there seems to be a different purpose than the QB's comfort with the ball.
Think about it.
Try stripping the ball from a running back that can squeeze a ball and dig their fingers in for grip, or stripping the ball from a receiver that's made a catch, or stripping it from a QB that's going down for a sack, when they all can squeeze that pig like a sponge.
I think if someone were to put the time and effort in to do a good statistical study, you'll find that Tom Brady, and the New England Patriot running backs, and receivers do not fumble the ball very much, and you'll probably find that players that have played in multiple teams, fumble less when they are in New England, and if you are really good at statistics, you can probably go back in time and find the point where they started deflated balls regularly for that purpose.