it became about more than equipment or air pressure when the investigation was impeded. This is an integrity issue.
Also, there is a huge value to the league on protecting the commissioner's final authority.
Anyone who pretends this is about ball inflation is just trying to distract for the real power play at hand.
That said...Brady is a cheater. 
On this, you are correct, the issue is about INTEGRITY, which should supersede who has more power over whom, or who has the bigger.....hands. Labeling someone as careless, or inattentive to the rules, is considerably different and far less destructive than labeling him a "cheater", especially for an accomplished professional athlete.
It would seem appropriate, if not NECESSARY, before throwing that accusation about, the accuser had HARD PROOF, rather than simple conjecture and personal opinion based on little more than," by guess and by golly" to casually tarnish, if not destroy, a hard earned and laudable career.
We, in a business of unreasonable expectations of absolute perfection in an environment of almost constant judgment of the significance, or insignificance of almost unending missteps of varying degrees have a special opportunity to consider actual violations of integrity as opposed to relatively common oversights.
Once INTEGRITY is recognized as the issue, it would seem a burden of ABSOLUTE PROOF (should) become necessary