The idea that's it silly if a player establishes it, but perfectly reasonable if the GM establishes it, is to me a manifestation of an assumption that play should be predominantly GM-driven.
That is, of course, an opinion.
But saying that the background world is described predominately by the GM does not make the game GM-driven.
I don't remember. I don't think it came up. As best I recall, once the PCs had established their bearings in the dungeon, by reading the runes, they headed down to the Vault of the Drow.
(Also, in case it's not obvious, there was no map and key in this game. MHRP doesn't use map and key resolution.)
That was rhetorical, mostly, but this very much is my point. If there's no known exit, then you have the PC/player not only create the meaning out of nowhere, but you quite possibly had them determine the shape of the dungeon by creating, or at least pointing out, the exit--something they should have no knowledge of. Neither the PCs nor players created the dungeon. They were not its architects or builders. Why on earth would they know where anything is? Why
should they?
I'm assuming that MHRP is Marvel Heroic Roleplay. I admittedly am more of a DC girl, but I don't think there are a lot of dungeons in Marvel comics, and those that exist--counting locations like Doom's castle, Prof X's seemingly labyrinthine school, etc.--change layout as the plot demands. So of
course there's no map and key resolution. You're almost certainly trying to put a square peg in a round hole here by using MHRP for fantasy without taking the genre switch into consideration.
I'm not sure that all do. For instance, some "cozy" RPGs seem to emphasise tea parties and the like.
You're assuming that conflict = combat and that's not the case. Conflict can also mean disagreements or minor disasters. Like
oh no, the souffle has fallen and her Ladyship will be here in less than an hour! What will we do? The term
rising conflict can be exchanged for
rising tension or
problems in RPGs.
Some dungeon crawls, also, don't really have any sustained rising conflict. Eg White Plume Mountain is more like a series of puzzles. There are very local moments of rising conflict - eg you take of your amour to get through the heat induction tunnel trap, and then get beaten up by the ghouls - but it's not sustained in any way. (And it does not cross a moral line.)
Conflict--tension, problems--shouldn't rise all the time anyway. Players and GMs get burnt out and it makes the issue unimportant. You don't
want to conflict (or tension or problems) to be sustained throughout the whole thing. An action movie that is 100% action is generally dull--there's no room for character, plot, or anything else, even the minor amounts of it you tend to get in an action movie. Same for RPGs. They should be a mix of slow and fast, calm and tense.