Let's get away from trying to pigeonhole various peoples, races etc because I think most of us have seen cringeworthy moments out there in the wide world from all sorts. It is true that certain cultures are far more respectful and have far more strict social customs than ours, and some have very different ones. I, for one, can not imagine a boorish Japanese tourist, but the odd one must be out there. I just thing stereotypes are not a great thing.
Sadly though I find myself embarrassed/cringing at some fellow aussie "antics" out there more than others but I'm not responsible for those just because I share citizenship.
Back to lounges.. the thing that bugs me is that there's a certain type of person who will treat an airline/airport lounge like their loungeroom at home, and not the public space that it is (I classify the SQ "The Private Room" as public too, despite the name - though when I was lucky enough to be there last week everyone was well behaved, with the exception of someone's really LOUD phone ringing lol).
My point is that the people that think it's OK to put their feet (bare or otherwise) on tables/furniture, or have loud profane discussions in person or the phone, or what have you do so because they treat the place with a different sort of attitude that most of us have. I enjoy lounges absolutely. I also try to be quiet and respectful when I'm in one - mostly alone, but if I have company I keep conversation quiet and certainly do my best to not slip a bomb or two(which I may do in my own lounge room) and generally be aware that other patrons want a quiet and pleasant environment.
As I often opine in such threads when they crop up, to me it comes down to basic common courtesy, consideration and manners. Many of us have been brought up with them and it's a default setting. Some others.. not so much. I think the same set of manners should apply wherever I am - the beach, the QC or TPR, or the local maccas. That's just me though.