I don't have a problem with some comping, or at least a promotion like Starwood had, because it required that you stay several stays in a short period PRIOR to the "comp."
I became a UA premier through a promo back in 1992. I have been 1P or 1K since 93 (earned). Alaska comped me MVP about 5 years ago or so. I have been MVP or MVP Gold since that time (earned). With limited exception, I'm not going to get on an airplane anymore without some preference. So if someone else wants my business, they need to send carrots first. As an MVP, I wrote to NW (Alaska's main partner at the time) about a possible comp, as I was an MVP and a UA 1K and they told me to go...... And so I haven't flown on them in several years.
Yes, I have earned my Starwood Platinum and had earned my Westin Gold, for several years. But I recall the original Westin gold was a promotional "comp." The thing is that if you are comped and then don't use the product, it doesn't hurt the rest of us. And if you use it occasionally, you aren't going to be renewed. I have been "comped" in several more programs that I have never used (the UA 1K list must be worth a lot) and then don't receive another comp offer for a few years.
So, the promotional "comps" have been good marketing tools as directed toward me, and have no inherent problem with them, so long as they do not dilute the ranks of the faithful patrons so much that they can never partake of the benefit.