If Christians can't agree on what the bible actually means, I don't expect we will do any better with coming up with a hard and fast definition os mustachianism, unless the MMM prophet himself wants to speak on the matter.
This is a truly baffling analogy. If the adherents to a 2 thousand year old religion based on a book - the New Testament - that is, in our language - a translation of a copy of a copy of a copy of.. we don't have the originals, and the oldest copies we have aren't identical and are nonetheless written in a different language altogether from that spoken where the events described occurred - if these followers cannot agree what it means, then how are we to know what Pete - a guy who lives about 2 miles from me - meant by all these blog posts?
Even when using the same translation of the same book, they disagree. Many, if not most, of the disagreements are far more about interpretation than they are about which translation is being used. And unless the MMM prophet is going to come into the forums and settle these disputes, we, like the Christians, are going to have to look at personal interpretations of the same words and the varied results of that.
So yeah, I think it's a pretty apt comparison. People read the some words and come up with different interpretations, different views on what is most important, and different approaches to integrating the teachings into reality.