Does a game need multiplayer to be good? Have you played World of Warcraft? There is no community, you can do nearly everything in the game without ever communicating with a player.
Diablo 3 was decent, about what I expected from a sequel to a game released 12 years after the previous in the series. The 'community' is pretty much 'lol mi charctur better dan urs look mi armory'.
But we weren't talking about community, were we?
Also, DF doesn't make money, it's pretty much a side project.