"Specialization is for insects." - Heinlein
Why not? Sure, DoF is has an MMORTS aspect but it sure can (well, looks as if it can) hold its own even as a single player. Besides, single player on easy mode is a way of building up a castle how one wants without the threat of constant player invasion. Or hopefully, at least. Until Reverie adds a Sandbox mode in a later patch (expectant hint

).
I'm not one for competitiveness in any case, so single player should take the edge off.