Or theirs might be to have the most fun possible as well doing the first. No one is right. It's all how you want to play. Designers get into trouble when they don't realize the genre they are in.
With that said the equation is pretty simple. Longer leveling curve, more zone content, no instancing, server based = player community, interaction, and less accessibility. The other way is getting content you want to play and having it there when you want it. I don't think we will see much of the former anymore - not because it is bad, but because the market content consumption model has shifted and shown enormously advanced profits and revenue towards the latter. When you get a company that doesn't care about blowing it out of the water from a profit center but can still have enough resources to design a game of this calibur, there will be move movement.
For example, if I win the lottery, I guarantee you I will make one.