Concerning Asia, I've been in Korea (Seoul, Busan, Seroksan), in Japan(Tokyo, Kyoto, Kanasawa, Miyajima,Nagasaki, Osaka, Ube, Hakata....the list is long) and in Taiwan (mostly Taipei) and must say I don't have the same opinion :
- Concerning Seoul (a city I really like) I was there 3 times (about a week each time) and if it's less "clean" than most of Japan it's not that stinky. It's like everywhere...yes garbage stinks ! lol But honestly Paris stinks more if you want to compare to another country. (I'm french so I guess I can say it^^). The interesting thing for me about Seoul is that there's area that are very modern and "high tech" and other area that are old fashioned. It's the mix that made it cool (for me). I've never been in these countries but when you say "poor South East Asian country, like Vietnam or Thailand" I felt offended...not to mention that there's poorer south east Asian countries...Don't ever go in Taiwan if you don't like motorcycle...there it's still the trend (it was awesome yet a little not Eco-friendly to see it). South Korea and Japan are two different countries so it's kind of normal that they're different. But to say that South Korea is like "to be more of a third world-country" is going too far.. I don't know where you come from but if South Korea is a third world-country...France is still in middle age then !
- There are tones of thing to do in Seoul for tourist ... of course it depends of what you consider fun...I went to several aquarium, to the grévin museum, trickeye museum, lotte world (it needs more than a weekend) ....the list is really long...also you can enjoy a walk in Cheonggyecheon stream, the 24h market, Dongdaemun Market or also shopping complex. You can also take part in cooking class, pottery class...honestly, Seoul is big and have lots of fun things to do.
- Most likely the people that didn't help you didn't speak in english...maybe some didn't want to help to..but to say they were cursing you..it's a bit too much...
- Korean like every other people in the world react on how you are with them...of course some people are rude but try to go in a Paris Café and you'll know the definition of rude people. It's everywhere the same some people are nice some other not. But as I read your post I felt that you were thinking that it's mandatory to be kind, smiling and willing to bow to you if you're paying for it. Sorry but it's not. People working in Seven Eleven or CU don't have huge salary and often work long hours...if they were pointing you to a seat it's maybe because they didn't know how to say you can sit there in english or were simply busy taking care of other customer, simply doing their job on a busy time...
As I already said people react on how you are with them...a smile, a thank you, a welcome is not something you can buy...you said you were in 50 different country...I'm really curious to know which country...because you sound very close minded and it's rarely the case for someone who traveled a lot...
I don't think you point of you is "from a completely neutral standpoint" cause you seemed to have preconceived ideas about lots of things...
I'm sorry for the long post...but your original post was very rude and also filled with negatives things so I had the urge to respond to every point of it...