When 11 of 12 balls are underinflated and out of the allowed range, that's not a coincidence. And no, the weather wasn't an issue, because the Colts' balls were all checked and all were inflated properly. Obviously if the temperature was a factor, it would have affected the Colts' footballs, too, not only the Pats' balls.
Somebody within the Patriots did it. Was Belichick aware? Was Brady aware? We can't say for sure, but it's obvious that when 11 of the 12 footballs were underinflated, it's not a coincidence. It's not the weather. Somebody did it.
Is it important in the overall scheme of things? Of course not. Global terrorism is a little more important.
But if the Pats cheated, it's important to the NFL. And notice how they are conveniently not making any announcements on their findings before the Superbowl....