AD is broken. Let us admit this and move on with a plan.

[mvossman]

So by this evaluation of AD, WHY would any team offer salary relief to take on this burden?

The only hope the Mavs have of coming out of this is a choice of:
A) pay to get off his money
B) play the contract out and get cap relief when it expires

We do not have the type of assets to pay to get off his contract and still have any hope of building a team around Flagg.

I am rose colored glasses hoping that this description of AD is more a reaction to scar-tissue from the Luka trade than actual objectivity toward him.

I think the OP is overly harsh, but there are arguments that AD has more value to some teams than he does to Mavs (who are building around a player that just turned 19).  There are or will be AD trades out there that make sense for both teams.