I think Tom911 comments should be interpreted as "it's nice to be appreciated and recognized for being loyal to airline" --it's not about FA messing up procedures and creating unrealistic expectations amongst passengers. (Although there are always a few rotten apples in the lot, if you assume the worst and take actions accordingly, it usually end up being the worst)

I certainly appreciated being thanked for flying UA two weeks ago by the ground personnel, regardless of mixed feelings of the UA's deterioration of mileagplus program.