How can you blame DD for Betts when we have no idea how much Henry authorized to offer Betts?
It's not like Henry hasn't made lowball offers to other players. Meanwhile, DD likes big offers.
The only reasonable conclusion is that Henry did not want to offer what Betts was willing to accept, not even after DD was gone. According to Betts, the final offer came when Bloom had taken over, and it was so low that his team just said no thanks, see ya later.