Anything Cox, CDK, or Cars.com related is a complete waste of dealers time and money. Regardless of their spin, those companies are in it for themselves. They care enough and satisfy a paying account enough to make it happy.
For a part it's a dealers fault but I blame these high dollar companies for over selling their company. I really wish dealers would would grow a sack a ditch AutoTrader and Cox including ddc.
I think that's a bit harsh, but I understand your point.
I don't think the rationale of "in it for themselves" is a great argument when there's many other reasons these companies are less than ideal - I think every company is in it for themselves to a degree. The ReyRey and CDKs of the world are probably scared of everything that could come in (ie: DealerSocket making a DMS, Silicon valley entering their space, etc) and they're being incredibly rigid and difficult.
Hide your disdain for your competition and let your products and solutions punch holes in them... one client at a time.