I cant accept that. You don't blow up the process merely because there is negotiating going on. In this case, the Dems chose to abandon the process before it had run its course and before they had moved an inch off of their beginning proposal.
Had the Republicans in frustration called off the discussions at the same point, that would have explained itself, but not the Democrats who now appear to have wanted nothing more than to be able to say that they tried but it didn't succeed, therefore they're safely off the "reaching across the aisle" hook. They know that the people want bipartisanship.
Besides, Trump is well-known for being a bargainer and that he did a lot of compromising in the tax reform and Obamacare repeal efforts of recent memory.