I think comments like "There once was a day when Marriott really cared what we thought. I've noticed that days of wonderful service at Marriotts seems to be a thing of the past." are gross over-generalizations and really quite silly.
In most cases it really comes down to local management and people. I may be a fiercely loyal Marriott guy but I can still be honest about the service I have received. I
have gotten exceptional service (Lihue, HA &Norwalkand Fremont CA Marriotts) and horrible service (Oakland Airport Courtyard). But overall Marriott is a great company and of course they care about what we think!
You are bound to run into some bad apples but for a large company, I have found they do still aim to please.