My wife is from Thailand and I've lived there for a while, I've noticed the same thing there with Western fast food chains. We think of KFC, Dominos or Maccas as junk food but over there, they are considered "mid range", as a result they are much cleaner and better staffed, the venues have much nicer seating etc. - this is especially true in regional areas, much less in Bangkok and other urban areas where I guess the novelty factor is long gone.