To address the OP, If I'm still playing, I'll pay. The reason for me is simple. The amount of detail that goes in to each one of these creations is considerable. Quite simply, they are frickin expensive to make. So the choice before us is: no new DG's ever (barring expansion pack) or we pay for new ones. The amount of money they would blow creating a detailed model, skins, animations, skillsets, voice overs, play testing.. it's just too much to be free. If the graphics were DoTA level with no voice over, it would be another thing. Part of the appeal for Demigod, for me, is that it's as much a work of art as a game. You gotta pay for that level of quality.
As to the aspect of feeling like you got cheated if they rebalance them, speaking for myself, that's not what I'm buying the DG for. Besides, by the time DLC comes around (if it does) modding and the SDK will be in. If we don't like the balance on a new DG, we can make a balance mod to address it. Pirate mods won't happen either, that one is easy to control for Stardock. New DG's could be made by the community, but it would be very unlikely as modders don't typically have access to Granny.