Correct me if I'm wrong, but I believe the Pats had their #21 stickers on for their game with the Ravens this past Monday night, and I believe last weekend was the only required weekend that teams were supposed to have the stickers on. What each team and each individual does is their own business. Class or respect has very little to do with it. The Pats paid their respects and decided to move on. Other teams have decided to leave them on. So be it.
From Monday night game vs. Ravens: