2dmoon,
You have either not read my post correctly, or you have interpreted it wrongly.
I have not said anywhere that the CC should not be thanked... it's the manner in which it is done I am questioning.
Washups, thanks, admonishments should be done away from the public.
Also, from a good man management perspective, your comment about the Tesco analogy not counting is wrong. It does not matter how often or regularly you work with someone, if they deserve a plaudit, then they should get one.
If it has been a trying day filling shelves or on a flight tending to difficult passengers, then a word or two showing appreciation of the fact should be given. Of course as you say, it is polite to say thank you to the CC, but why does it need to be done in front of passengers?
It can be done much more personally after the passengers have gone... face to face which is the proper and respectful way to do things and which carries much more sincerity.
I don't have a bee in my bonnet about this, but IMHO it's not about politeness, it's more about the way society is discarding perfectly acceptable (possibly more genuine) protocol which has been around for years in an effort to be seen to be fluffy in front of others!!
You've maybe guessed I don't like Marmite
!