Hm. I think of things like this.
When I get up in the morning, I've got a limited amount of time and patience for cooking breakfast. Now, I may not know what kind of breakfast I want. Do I want some eggs? Do I want some toast? Do I want some bacon?
Sure, let's pick eggs! I get out my pan, get the surface all buttered up, get out my spatula, and crack my egg...
And a half-formed baby chicken falls out. Now, my appetite for eggs is ruined. Because I didn't want half-formed baby chicken, over-easy. I wanted eggs.
No big deal. I also wanted toast! So, I take the butter from the pan, get out the bread...
And it's covered in mold. Well, bugger me. Now I can't have toast either. So, the old fall-back... bacon! I get the bacon out, determined I am actually GOING TO EAT BREAKFAST before my patience runs out entirely and I have to leave the house. And, what's happened? The bacon is rancid. Well, slap me on the butt and call me "Sally." At this point, I'm hungry, haven't had a satisfying breakfast, and I no longer have time to cook my own. I have to get some McEggs or something on the way to work.
That's the way dungeon-crawling is. Even if you manage to get a party together for long enough to walk somewhere, and RP the entire time, the chance of the dungeon being at a good spawn (or, challenge level, if you will) is random. Not really random, actually... with the things are currently, chances are the spawns are less than full. So, you get there and the dungeon is torn apart already...
By the time you and your party has walked to the next place, you run the risk of someone dropping out of the party and - if the party is balanced at all - people had their purpose and any one person dropping out means part of the experience is going to be ruined. Thief drops out? You're getting no loot. Fighter drops out... you're not going to be able to kill anything. Support sorcerer or priest drops out... your fighter is going to get slammed by the fact he doesn't have a +2 weapon, protection from evil, or any number of other things. And if someone drops out, rather than let the whole affair go tits up and leaving everyone left unsatisfied, chances are you're going to end up calling another person OOCly and concocting some reason for them to meet you, just to keep the experience satisfying.
So, that's why the smart consciencious people communicate OOCly about the spawns before they head out.
Randomness and the thrill of not knowing what will happen can be fun, but you -sorta- want to have an idea of what's going to happen. When I wake up in the morning, I want to know I've got *something* palatable to eat. I don't want to wake up, thinking "WOW! It's so exciting! I can't remember if I actually have food in the cupboards!"
That's not exciting. Most of the times when you do that, you just end up hungry and grumpy all day.