Teams have to have a structure and pay scale in mind when they deal with players because one deal most definitely affects another deal.
Players generally understand that special perks are often given to premier QBs that other players just won't get; the most money, more guaranteed money, more injury protection for the player, etc.

But what happens if you extend that to a DT? It means that you are making it more and more difficult to keep your players within a structure and able to keep as many good players as you need.

Keeping a premier QB at all costs is understandable. Keeping a premier DT at all costs is not.

And the fact that Donald may be getting upset is just the way it goes. We can talk about him deciding he no longer wants to play for the Rams and all that stuff; but he doesn't get to choose. It's the Rams or nobody. Unless of the course the Rams chicken out and trade him. And don't even think they'll be able to get his value in trade.

Cum ba Yah between player and team isn't needed in a world of very high finance.