Of course, nobody has a gun to anyone's head when it comes to playing an MMOG. However, there are two entirely different modes of playing particular content in any MMOG: the content you have to play, and the content you want to play. Sometimes it's the same, but a lot of times it is not. Many players have the sense that they have to grind the repetitive kills, quests, battlefields or raids to keep level with their friends, or for their guild, or just to compete overall. With others it's just a sense of having to do what they can to level their character or acquire the next ability or advancement; at some point, it can become a burden between you and what you'd rather be doing in-game.
A lot of players would really rather log in and focus on socializing, exploring. role-playing or other activities, but many find themselves torn between what they want to do in the game, and what they feel they have to do in order to advance their character, because IMO one of the greatest pleasures in an MMOG is that sense of managing the advancement avenues of your character.
Now, I'm certainly not trying to cast any playstyle in a bad light; we all have our preferences. Also, there's a lot of people who truly enjoy the at-the-keyboard, online-time-invested competition of character advancement; but there's plenty of games for that particular enjoyment. There's a lot of us who really don't want to spend our online time "grinding" in any sense for character advancement; honestly, why not let the character do that on their own?
How about a game that lets the characters do all the boring, repetitive, grinding stuff on their own while I'm offline, so that when I come online, I can do whatever I want to do, and nothing that I feel like I have to do. Let me set my character to grind for gold, or collect ingredients, or train to advance levels in whatever category I wish while I'm offline. That way, when I come online, I don't have to choose between things I want to do, whether it's raid, or group, or role-play, or socialize, or explore, or go do various quests (once, for god's sake, just once).
Eve has a good interface for offline advancement, but IMO it just doesn't go far enough. Why not open everything possible up to offline advancement? That way the only reason we're online and "in the world" is to do what we want to do. It seems to me this would cut down immensely on burnout and frustration that inevitably comes with every MMOG currently available.
Furthermore, just think of what offline progression would mean for casual players who want to experience more of the game from different class and race perspectives. As it stands now, casual players have to limit their experience of the game to one, or perhaps two, characters because they just don't have the time to meaningfully advance more than one or two characters significantly. Every time they log in, it's a choice between advancing one character or another, or socializing,or role-playing; with offline progression, they could be advancing an entire stable of characters 24/7!!!
If a lot of the fun in an MMOG is character advancement - being able to choose traits and skill pathways, making decisions about talent and specialty trees, just think of the fun of being able to manage the 24/7 advancement of a whole stable of characters, without having to grind any of them at all!
All it would take is an MMOG developer that moved the focus of the player's involvement from character advancement grinder to character advancement manager, and let the player decide what aspects of the game he or she wants to play, instead of "forcing" them to spend online time doing things they'd rather not.