I think you may be misunderstanding the entire premise of Belichick's philosophy, and that is why you are upset.
It isn't about disrespect, and it isn't about "not being a part of the team."
It's simply about resting and healing your body and injury, and there really is no particular reason to physically have to come to the game knowing that you aren't going to play. There is no possible way that anyone in that situation can contribute to the team on any level, so Belichick feels that the best way to handle things is to properly rest and heal so that you can come back asap and help the team on the field. They don't need leadership from someone standing on the sidelines, that's not how they work.
That's always been his philosophy, and I would imagine that there are certainly other teams who do the same.
As far as sitting in Kraft's booth, that is usually just done for the higher profile team leaders in certain big game settings. It's not like Gronk was sitting up there the whole time he was out. He actually commented quite a few times about having to watch from his couch at home.