Why are Michelin tires constantly out of stock?

A few years back, my stepfather had to spend a few days in Billings, MT waiting for a Michelin tire to be delivered for his MH. He now carries an unmounted spare tire. He is not much of a Michelin fan any more because of that, since tire had less than 2000 miles on it, and they said it was "customer abuse". A term I became very familiar with when I was a dealer. :R