Which is of the essence of humility, of course! 
Or, perhaps it is a good indicator that his extreme conclusion on the matter cannot be taken seriously. We ALL know something is radically wrong in Rome and has been since before most of use were born. Otherwise, none of us would be in Traddieland. SV is a perfectly rational take, even if one disagrees with it. Those who believe SV is non-Catholic, schismatic, etc (or who think the same about SSPX-ers, et alii) are part of the problem and just embracing the dogmatic version of whatever flavor of Traddieland gels best with them (for now).
I, for one, never indicated that this James Lofton is humble. But that doesn't mean that he cannot make a few good points, as well as some wrong ones. The Dimonds do the same, and they of course are far from humble. Humility isn't really a sedevacantist virtue.
I don't agree that SV is rational. Nor, on the other hand, do I believe that it's schismatic, but it can lead to schism. Therin lies the problem, IMO.
In doing more research on James Lofton, it seems that he is a fan of Siscoe and Salza. Not surprising, given his view of things sedevacantist. But that doesn't mean that I write him off altogether.