I also feel that this game feels like a single player game more than an MMO. The main reason for this is that when I log on I feel as though my progression is on serious rails from which I can deviate, but not very meaningfully. In contrast, an MMO has the feeling of "ok, I'm out in this crazy world with all of these other crazy people... whats gonna happen next?!?!" In this game I know that what is going to happen next is more or less what happened to the last guy who decided to roll this particular class, because that is how this game is. Yes, there is variation and other means of leveling/playing, but the amount of variation feels minimal compared to what I have come to know over the years. So, if you are stumped about people saying this feels like a single player game then focus on the notion that it FEELS like one, rather than that it IS one. You are correct, it IS not a single player game, and yet it does FEEL like one in many, but not all, ways.