In no particular order...
AD isn't likely to get hurt while he sits out.
I'm sure that he's in excellent condition and knowledgeable about Wade's D.
Other players are getting valuable snaps.
AD will probably be up to full speed within a week of his return.
The regular season is still over 6 weeks away, so what's the rush?
Rams are saving money by pursuing this non caving strategy, money that will help sign future players.
An important precedent is being set while agreeing to renegotiate a star player mid contract, yet not seen as caving.
This will work out such that all parties will walk away happy.
