I don't stay at Marriotts exclusively; I'm as sensitive to price and convenience as the next traveler. Why have I chosen Marriott so often? Partly because they build or acquire properties in the right places. Location, location, location... just like McDonalds. But there's a reason why I give Marriott the nod when all other things are equal.
Like McDonalds, Marriott strives for consistency. This was pointed out to me by a colleague, Rashid Rafek, on a trip to Utah in 1988. (Rashid, a Muslim, was fascinated by the Mormon lifestyle we saw. It still saddens me that Rashid died in a car accident a few years later.)
The noteworthy things about Marriott -- cleanliness, responsiveness and attitude of personnel, etc -- are not merely good. They're predictably good. I can take for granted that when I check into a Marriott, it will be good. That's not the case with Hilton and Sheraton, where I've slept about 75 nights each. I never know what to expect from those brands. When you're on the road for a large chunk of your life, consistency matters. I can count my bad experiences at Marriotts during 30 years on the fingers of just one hand.
That's why I fly American Airlines, too. Like Marriott they're not the best, but they are good and they are predictable. I could have said the same about Delta until 1995 when they fell into a terrible funk. Fifteen years later, Delta has regained its footing. Better late than never!
United and US Airways? Don't ask.