Because it was fresh, flavorful, original, immersive, the stories were great, the design was great, and you had fun right from the minute you logged into the game. There was no "this game will be super fun once I _______!!!!". Most people didn't reach endgame or even care if they reached endgame, they just made tons of characters of different races and classes because they were that interested in just seeing the world and it's inhabitants. The PvP was fun and made the world actually feel dangerous. The factions were amazingly designed, the way you had to cross into enemy territory early on just to level was amazingly designed (pay attention ESO) and it bred pride for your faction and hatred for the opposing faction. No cross-server/dungeon finder meant you actually made friends and remembered the people you grouped with. The extremely specialized/unique classes may have been unbalanced, but they made people actually rely on each other. Classes of even the same role had huge holes but at the same time they also filled niches that only they could fill. It made you necessary, and it made you proud to be playing the class you were playing. People didn't just rush to endgame to show off their leet gear, or grind the same dungeons over and over for no reason other than to justify to themselves that they were paying a subscription. The game could have been single player and it would have still been fantastic (how many MMOs can you say that for) and then on top of that, the multiplayer component made the game 100x better.

Remember when RPGs actually told great stories (both visually and through dialogue) and actually drew you into a world? Yeah.

lolnostalgia!!!11