The guaranteed late check-out is a benefit I take advantage of on the majority of my Fairmont stays.
For me, what keeps me coming back to Fairmont (and I seem to recall discussing this on another thread recently) is the exceptional service. Also that they have a few properties that just happen to be my favourites, which I return to for holiday regularly. I like to think I'd still get that service even if I wasn't a platinum member, because I think great service is just part of the culture practiced by Fairmont staff.
Loyalty programs in general aren't much of a driver for gaining my business. Certain perks are appreciated, but I'm not likely going to choose a particular hotel because they give the most points or the best amenity kit. I choose Fairmont whenever it's an option because of the service and also because it has become familiar and comfortable to me.
It's the same thing with airlines. I'll fly with the airline that gives the best product and timing on the route I want to fly for the price offered. Any statuses that I've earned and subsequently lost over the years are more accidental in nature than planned.