Adventure mode is certainly very advanced, but I wouldn't call it that fun. The combat system's accuracy is both its strength and its weakness. While the realism is extremely impressive, it also means that you can die no matter how well you prepare. An arrow or fist to the head can end you at any point, making it very easy to get frustrated.
When you take another popular rougelike (Nethack, in this case) the focus is much more around preparation rather than grinding. The hunger, rather than being an albatross around its neck, is in fact one of the driving aspects of the game, a constant impetus to move forward that keeps you from grinding in a fashion that is engaging, rather than frustrating. Yes, there is no thirst, but do we play games to deal with reality, or to escape from it? If you take the first objective, DF AM will do that for you, but if reality made a fun game there would be much less focus on interactive media in general. There is no situation you cannot escape in Nethack. Asmodeus has you cornered? You can engrave Elbereth, teleport, invoke the Orb of Fate or Eye of Aethiopica, or quaff a cursed potion of gain level. Conversely, if you get knocked down by something big in DF adventure mode you are pretty much dead. In addition,
AM's greatest strength, its detailed targeting and damage system, is greatly reduced by the fact that most hits are either 'probably' going to hit (ie. being oppurtunistic with legs, arms, & body) or 'not going to hit excluding high master or higher' (eyes, throat anyone? A blinding move would be nice)
I'm not saying adventure mode is horrible (it isn't) or that it is unenjoyable (it isn't) but rather that it creates an atmosphere of frustration by encouraging grinding and then killing you with events beyond your control. It has amazing potential, but to cultivate that potential it should probably take a look at its design philosophy. (IMO it's a lot more fun to see a fort go up in flames than to die in AM, if only because the deaths often seem spontaneous in AM)
Iunno, a lot of what I don't like about the game other people probably do like though.