I think complex games and "shallow" games can co-exist. About Tabula Rasa etc, I believe WoW is quite popular and can be quite complex (from what I've heard) if you want it to be. I think that's the point, you have to think about making your learning curve reasonable and rewarding. If you make a game that's just boring and frustrating the first hours, many people will just give up.
This relates to the story thread. Morrowind is a good example. You can just mess around and have fun, or you can really get into the story, read all the books etc. Play it the way you want.







