I suppose it would be churlish of me to point out the factual error in his article regarding the frequency of non-US Worldcons. Alas, he's not the only person to make mistakes of this sort. For example, I met a fan a few years ago who confidently announced that Australia's 2010 Worldcon bid "wasn't allowed" because "the rules require the Worldcon to be in the USA in all even numbered years." She had never actually read the rules, but generalized from the only experience she had, which had the 2002, 2004, 2006, and 2008 Worldcons in the USA and the 2003, 2005, 2007, and 2009 Worldcons in other countries. Having only encountered Worldcons from 2002 and never having looked at any history, she generalized from insufficient data and drew a bad conclusion.
Based on this same sort of generalizing-from-insufficient data, I suspect we'll see people making Bova's same mistake, as they'll only take 2010-2014 as their base set and assume that "the rules require" that every fourth Worldcon be off-continent, with the other three required to be held in either the USA or Canada.