Let me start by saying that I agree with you (I remember the times when I used food flavours to talk about Elemental back in the betas pre-1.0... now I talk about pants, apparently).
One reason by which it's difficult to dissapoint me with the game is because I actually set my expectations very low (see OP for some of the reasons) and follow the "As long as it's fun" motto. That doesn't mean I end totally happy with all its elements (Dynasties, I'm looking at ye in your latest incarnation!) but it would require an apocalypse to freak me out.
I'm happy that you mention dungeons because that's one of those things with some meat to talk about. Yep, this is no RPG and explorable dungeons by themselves are a bit off of the TBS that Elemental is (if you start with different levels, fog of war to explore, treasures, parties limited to champions, etc). But it also depends on how they are done. And forget about Multiplayer.
I must agree that Tactical battles also break the pace (in the same manner) but as they are more popular (and already in the game), it seems easier to ignore that and keep them. And our current Tactical battles are quite easy without complex ability system, complex city defense, complex battlefields,... huh? Imagine if they had all that stuff. Hell, some people would prefer city development as reduced as possible because for them it breaks the pace they like (war, war, war,...). What was the OP about everybody wanting something different?
It has already been mentioned but if it hadn't, I'd mention it myself: if you don't add them in some way (which as I said, I agree with your reasons), make sure to give some serious modding tools that allow such a thing. We can link to different maps (Tactical maps) but actually having people being able to add extra planes to the game, explorable dungeons and similar stuff are one of the things that the most serious modders of the community (of which I'm not one ) could appreciate (and lets not talk about the players, specially MoM's ultrahardcore fans of doom). I suppose.
Maybe people would develop explorable dungeons as tactical maps (one or some linked) with "dungeon" (or sewer, palace or whatever) scenery (blocking paths and all that), with some triggers for "events", FoW for exploration, maybe battles go in their own tactical map or maybe enemies are placed on the map and move, etc. Maybe some prefer explorable dungeons as a mix of text-adventure and some tactical battles tied to it (lenght and difficulty based on the dungeon). There could be some that having explorable dungeons as pure text-adventures a la Space Rangers 2 * (I made a thread about this long time ago in the modding section) would be more than happy. Oh, and if someone mentions "We suck at writing", then I should say "HerrGamenon, I choose you!!". One of the things I want in the game are text-adventures. By mod or by Stardock. Hell, I would love to make a game (a real game, not just a mod) around that.
As a reminder, I agreeded with the OP about the canon game.
* great example of mixing different things and not "breaking the pace" and keeping some as optionals.