People tend to assume that mod tools ensure the longevity of any game, but in fact that may not only be wrong, but having too many mods available may actually have the opposite effect. Food for thought.
While your Psychology 101 prof will certainly approve, let me point you to the beta and SupCom. We had modding in the beta, it was not supported, it worked anyway.
There are already mods that improve Demigod, due to lacking mod support you can only use them offline.
In SupCom a few mods became extremely popular and a huge percentage of players used them. SupCom would have missed out on so much without Sorians and DuncanEs AIs, the GAZ_UI, Zulans Hotstats, Replay Manager and Analyzer... only to name a few.
And for those who are concerned about cheating: You can lock the game files with an md5 hash check and allow to mount mods from a special folder via GameDataPath.lua. In tournaments and ranked games the folder is disabled and all mods switched off. This system is easy to implement and as foolproof and secure as the current 'protection'.
And a lot of us enjoy modding the game as much or even more than playing it. One of the reasons I preordered Demigod was that it uses almost the same engine as SupCom and I assumed we would be able to make maps and mods!