Wasn't GW2 supposed to have appealed to the Korean market anyways? I thought it was already hitting it big over there.
I seem to remember reading an article after the first Chinese Beta that Korean players were upset the game was launching there first. Can't seem to find it now, except quoted on a bunch of obvious goldseller sites I'm not about to visit. The game has Korean text and Stormbluff Isle was home to a large Korean WvW guild (WarMachine) before they decided to get out of Tier 1.
This is specific to the leaders of the GAF guild though, and it permeates through about every GW2 thread that isn't in Community.
They're probably just stoked to have the only successful GAF MMO guild haha. That guild rocked.
I'll address your second comment first: The success of the GW2 GAFGuild has a lot to do with the nature of the game itself. First off, the game doesn't force you to pick who you play with. You can guest to any server in your region, so players aren't forced to pay for transfers (or start from scratch on a new one), abandoning their existing friends. You can also belong to multiple guilds, so if you want something a little more focused or hardcore than our very casual guild, you don't have to drop one or the other.
They're also very careful to create content that doesn't have a hard cap on the number of players who can participate. Other than dungeons, which have a 5-person cap for obvious reasons, any number of players can show up to Guild Missions. That means there's never any internal politics or drama over raid slots, who's in good with the right officers, etc.
Having said that though, the guild leadership, officers and general members are a great group of people who remain enthusiastic and eternally helpful. The atmosphere is overwhelmingly positive and helpful, there's none of the nasty backstabbing or forming of cliques like you get in most games. They've donated in-game gold to buy transfers for total strangers to migrate from EU servers to North America (guesting doesn't work internationally), donated to keep the guild's Mumble server active, and have a really good reputation on the server. They're a great group of people and it's been an honor to be a part of their community.
So to address your first comment, now, the reason you see the same folks from the GAFGuild community so active is simple; passion. It's a great game with a great community that doesn't deserve the hate it routinely receives on GAF. Not every game is going to appeal to every person, but that doesn't mean folks need to be bitter about the success of something they don't care for...