I really don't understand why Bill Kristol et al don't just get behind Johnson/Weld. I mean...they were good enough as Governors for the party, weren't they? Their views really haven't changed all that much. Ballot access in 49 states (and they may have it in OK this year, too).
I could see Kristol thinking something like "but the standard-bearer needs to be chosen by the elite establishment types like us for it to mean anything", but most of the types that'd be likely to vote for an independent conservative are in lock-step with Libertarian economy policy broadly speaking (worried about their personal incomes and levels of taxation, as opposed to those favoring subsidies for their industries and so forth, the latter of which makes up an insignificant sum of voters). They don't care about social issues one way or another for the most part.
Is Kristol still of the persuasion that they're going to be able to throw it to the House? Furthermore, does he believe that the GOP House would screw Trump in such a way when they haven't been willing to man up and attack him throughout this whole ordeal (perpetually until it was too late) or stay the course and try to pull the rug out from under him at the convention?
What makes you think people who would vote for an independent conservative against Trump mostly don't care about abortion or other social controversies? If someone isn't willing to support Trump, that's likely the sort of issue they are passionate enough about that it would keep them from supporting Hillary either. There are plenty who fall into this category, especially more educated religious conservatives.
And Kristol is a hawk, he wants someone more willing to be interventionist than Johnson.