This bizarre step can probably be explained by reading the blog of Arturo Vasquez, a proudly and decidedly cultural/ nominal/ cafeteria RC whom Och attempted to copy for the Orthodox world. You can be assured he did not make the switch because he cares about the dogma of the RCC, but because he wants to be in a messy "old world" church where he can indulge his Marxist fantasizing while still playing around with folksy Christian trinkets. Attempting to be an actual pious Christian is, in his view, simply a hopeless affectation; it's much more worthwhile to be apathetic, nominal, and therefore more authentic- since this doesn't work well if your religion isn't widely followed where you live, it makes more sense to switch to a more established and popular religion where you can join large numbers of other people in not caring about your religion.
What we have here is a very strange expression of Christian hipsterism. The posturing is so contorted and contrived that I doubt it could ever involve more than a tiny handful of people.