Conservatives in general and National Review in particular are perfectly within their rights to find Paul's views about blow-back, non-interventionism, and the undue bellicosity of the establishment wrongheaded, and to argue against his libertarian take on foreign policy. In the editorial above, however, Paul's actual views are egregiously obscured, and the editors seem to reach the transparently absurd conclusion that the popularity his foreign policy message has found is grounded in a conspiracy theory about 9/11 rather than understandable disgust at the actual foreign policy decisions made in response to it.
The evasive treatment of Paul's views and popularity is of a piece with the general refusal among movement conservatives to logically rebut critiques of American foreign policy made by libertarians and paleocons. The crank card and the 9/11 card are often the extent of their response.
Personally, I would not go as far as Ron Paul on a variety of foreign policy issues (pulling out of the United Nations for instance, and rolling up all overseas military bases) but it has always been curious to me why no other candidate would adopt a Ron Paul "Lite" approach. I thought Huntsman was heading there - but he's far too eager to start a war with Iran to plausibly be considered a non-interventionist.
It's not like such non-interventionist views are unpopular. Based on polling done during the Libyan intervention and during the Syrian uprising, the American people do not express a strong desire to poke their noses into other countries' internal affairs. They're willing to cut defense spending, too. I think that wariness could be effectively channeled without framing things as radically as Paul does.