One really can't blame McConnell for taking his "get a majority, then come up with a plan" approach.   After all, if GOP Senators had been voting on "unpopular" proposals,  the Dems might be controlling the Senate right now.

The fault for this fiasco lies firmly in the hands of Trump.  McConnell never promised that it would be "easy" to replace Obamacare, or that he had a plan that was "better and cheaper".   It was Trump who insisted that Congress abandon its "repeal and delay" approach used in the 2015 bill, and demanded that Congress "repeal and replace" simultaneously.    And it was Trump who took no leadership role (and who has consistently tried to claim the credit when things went well while shifting the blame when things went badly) in designing a replacement, or selling what Ryan and McConnell had come up with.