That interpretation is too simplistic. It might work for Rogue or the first few Nethack levels, but more advanced terrain gen exists, you know.
If you'll read what I said again, I didn't say that corridors don't serve a useful purpose, I asked what purposes they serve. Here are two fairly obvious purposes that they serve.
1) They are the route through which players and monsters move from room to room within a dungeon level.
2) They demonstrate the geographic relation of the rooms within a dungeon level.
When you said "If the only thing they do is carry the player from one challenge to the next with there only choice being which door you kick open, that can be handled with a dialog box and an ASCII cut scene", I replied with the first sentence in my last post, implying that I believe this is a false sentiment. If that wasn't clear.
"What other purpose could they serve though?" was answered by the third sentence in my last post, which stated that corridors are tactical chokepoints and terrain features.
Here are uses of corridors that can't be replicated with a dialog & cutscene:
+ A +
+ +
+ +
+ +
+ +
+ +
++++++++ +++++++++
A A
++++++++ +++++++++
+ +
+ +
+ +
+ +
+ +
+ A+
You can have two, three, or four intersecting corridors which connect two, three, or four rooms. The effect? The corridor becomes a chokepoint at any of the points labelled 'A', but loses its value as you venture towards the intersection. A player standing at the intersection no longer has the advantage of fighting against a maximum of two enemies, he can now be surrounded and besieged as if the area were a wide open space.
In fact, at the intersection of two corridors, you can be attacked from four sides without the possibility to escape diagonally. This means that the center of this structure is actually
more dangerous than an open space; the tight one-square corridors instantly reverse their advantages.
You can line corridors with traps, too. Any intersection can be given a higher percent chance to spawn with a bear trap or monster-spawning trap. Then you could also give the player an alternative route,perhaps an alternative wider corridor, to cause a decision to be made.
How about this:
+ A +
+ +
+ +
+ +
+ +
+ + +++++++++++++++++
++++++++ ++++++++++++ +++
A A B +
++++++++ ++++++++++++ +
+ + + +
+ + + +
+ + + +
+ + + +
+ + + +
++++++ ++++++++++ +
+ +
+ +
+ +
+ C +
+++++++++++++++++++++++++++++++
In this case, the corridor is more of a tactical decision. Say you are at point C, wanting to move towards point B. Do you take the open-space route where you can be attacked by monsters without a chokepoint, or do you drag monsters into the corridor, another potentially risky move? Maybe the monsters can push you back one tile, which in this case would shove you down the corridor into the intersection and possibly into any traps. In an open-space area, the push-back might be less dangerous.
Are there any other things they contribute? Because the only thing listed in this post that looks hard to implement using just rooms is exploration, and that's largely down to room design.
But the real question is: what is your definition of a corridor? How does one use "just rooms"? If you implement a chokepoint, at what point is it just a narrowing of the area, and at what point is it a separate concept?