I was there a couple of months ago. I've lived in Japan for a couple of years, I know about the importance of respecting other people's culture. Compared to Tokyo, Seoul was dirty, smelly, and everyone just seemed in a bad mood all the time.
When I was in a restaurant and asked for a glass of water, they told me to go fetch it myself, because the staff were fucking sitting next to our table having dinner. Wtf was that about?
Btw, Seoul was boring as shit, won't be going back there again. Seemed to have nothing to offer, unless you are a fan of shopping for whitening cream.
Hmm... do you have any other reasons to hate an entire country instead of those? Because what you just complained about, well:
a) People "seemed" in bad mood? Where? When? In the streets? If that's the case, maybe they were having a bad day, what's the big deal? And if they seemed in a bad mood, why not try talking to them and see what's happening? I never disliked someone because "they seemed in a bad mood". Maybe all they need is someone brighten up their day.
b) Koreans staff eat in the "costumer's table" all the day when it's time to eat. It's normal here. In America or anywhere, with a big stratified view of society, a waiter have to sneak back in the kitchen for his break. Here, they have a meal together with costumers. You misunderstood what he said. He didn't said "Go get your fucking water, prick", what he said is "Water here is self-served". In Korea a looot of places have self-served water, kimchi and pickled radish, ahd they have big signs telling you that, usually in front of your eyes when you seat or enter the establishment. Can you read Korean? You took too personally and that's it.
c) You took a look at Lonely Plant or the Korea Tourism Organization website? Seoul is a mixed city with a lot of old palaces and beautiful skyscrapers. They have TONS AND TONS AND TONS of shit to visit. Sorry, but everyone will tell you were wrong about this one. Absolutely every place holds some history. Have you ever been to Norayngjin, the fish market? Perhaps the palace destroyed by the Japanese, but reconstructed by Koreans? - Known as Gyeongbokgung. You took a walk through Cheonggyecheon? Because it is impossible to not fall in love. If you ONLY went to Myeondong, which is the area CROWDED with JAPANESE AND CHINESE looking for WHITENING CREAM, then yes Korea is gonna suck.
Yeah, looks like your typical case of foreigner who didn't do their homework and was received "badly" by the country. How many days you spent in here? Doesn't seem more than 4. Plus this is an asian country. As much as Koreans study english their whole lives, you WON'T be able to survive and have quality time here without knowing the basics.
It's a shame you had such bad impressions from here, but they are all your fault.
EDIT: You even searched for tour bus? Because that's the first thing normal people usually do in a country they recently arrived. In Korea you have a 10 bucks bus that's runs almost all day long (9am - 5pm) and everyone knows about it. It is in every freaking youtube video "what to do in Seoul" or any touristic info. Also in Korea you'll find flyers recommending this.