It's the whole game philosophy that has changed. No more open world. No more alliances outside of instances. No reason to group up outside of instances. No challenges outside of instances. No use for crafters or gatherers in endgame. No need for communication between party members (except in that brief interval between content being released and people being expected to know their role or get kicked).

1.x didn't fall because its design was flawed. It failed because its execution was. But SE couldn't afford to take the same chances and fall a second time, so they played it safe, made a by-the-numbers MMO and made it well. If only the same care had gone in to version 1.