I fear most people do not understand the problems with making a game multiplayer.
Either you make it a MMPRPG like Everquest or <anything> Online. In this case you do not need a dedicated storyline like Divine Divinity has. But you need servers and fight a neverending struggle against cheaters.
Or you make it a bit multiplayer via LAN or whatever for some people to playing together. You need the same story as you need for a singleplayer game. You have to put a lot of programming for multiplayer into the game and I do not believe that so much more people buy the game, because of the fact that it is multiplayer.
And as long as characters are not server stored, there will be cheaters. And even then there are cheaters. See Diable 2. I remember Evil Islands, being a nice RPG IMHO with nice features (for example creating your weapons from plans and materials), but the multiplayer community died because of too much cheating.
So, why should game designer make a game multiplayer, if they want to make a game with a great story, primarily?
