Wasn't Crowley the head cross roads demon? I doubt he'd be willing to answer the call now, or order an underling to do it.
They don't actually have a choice in the matter. You summon one and it automatically teleports to your location, whether it wants to or not. Even demons that aren't powerful enough to teleport on their own are subject to such summoning. It's one of the many small annoyances that come with being a demon.
Actually we know this isn't true. In the flashback to the time right after Dean's Death, the CRD that finally showed up to answer Sam was the first demon to actual show (after Sam mad multiple attempts), and based on further dialogue, I Don't think Sam stopped trying any time soon.
Of course this could be due to Lilith stopping the rank and file CRD (she at that time held all contracts, and she isn't a CRD, she was after the death of Azazeal the leader of Hell). So it seems that the current boss in Hell has a lot of say about the actions and the contracts of CRD. Though we do know that a CRD can deal without the big man's consent or knowledge, but we do know that the big wig holds sway over the rank and file.