He gives a brief explanation at the end of Localism and Globalism Again (and a Note)
In this post, Mr. Stegall links to an essay by Yasmin Alibhai-Brown: Seasonal produce: Think local, eat global. In it, she writes:
"The inwardness can develop into serious paranoia and a new form of tribalism."
In a collapsing society, tribalism will develop regardless of whether there is a movement for relocalization or not. What a movement for relocalization can do is to order tribalism towards the proper goods and make it humane. But it would appear that the author may have a vested interest in a liberal multicultural society, as she has benefited from it and is a true believer. Should we then talk about liberal paranoia of ethnic and cultural pride? There may be a right to assimilate, but there is no right to demand that a people change its mores to conform to your liberalism.
Liberalism's war against tradition and culture is sometimes overt, and sometimes it is subtle, but it is there. The discussion of local produce is just the starting-point for one liberal to defend her beliefs against what she thinks are threats to liberalism. (And perhaps rightly so, though she is wrong to claim that these threats are necessarily vicious or linked to evil.)