I think this is hitting on the nut of the thing. Some of us were chatting earlier and I mentioned something that we did in a D&D game WAY back when. Instead of acting like typical D&D characters, our PCs decided they would act basically a lot like normal people might, granted ambitious ones. So, we went to the Dungeon Entrance, after buying some men-at-arms, a couple crossbows, a couple big tower shields, and a mule. Now, we were pretty broke after that (we pooled our starting gold). So we carefully explored the mazy dungeon a bit until we found some gold pieces, killing a couple level 1 monsters in the process.
So, now we go back to the town, and the fighter goes to the local lord and says "hey, we've found a dungeon, if you give us an exclusive delving license, we'll follow all your rules, cut you in for your share, report all our hauls, and whatever other reasonable rules you want." So he says "Sure, why not?" Next we go to the moneylenders and get them to front us like 100gp for better equipment, and make them partners in 'The Dungeon Company'. Now we proceed to systematically exploit this dungeon like we're miners, not 'adventurers'. We build wooden hordings that we can push down the hallways, carefully survey everything, block off any area we aren't interested in exploring, and basically just do what any actual living breathing people that want to clear out a dangerous place would do. We plan out every little trap clearing op, build simulations of the complicated traps and work out how to disarm them under safe conditions, etc. etc. etc. Sure, there's danger, Jelly Cube eats one of our walls, we come back with lots of fire and that's that, etc.
The point is, this lead to a discussion of the UTTER CRAZY NONSENSICAL NATURE of the characters in adventure games of a D&D-esque ilk. What insane person wants to just do stupidly dangerous crazy things? Nobody in a million years would ever behave ANYTHING like a typical D&D character, not unless they were literally certifiably mad. People in the real world exist like that, sure, but most of them die young, and the rest are looked at a bit askance at the very least. They are also fantastically unusual, and I'd say that a game which can only handle play where that sort of character is ALL OF THE PCs is somehow bent. It sure isn't a very sophisticated RPG!
Now, we CAN come up with reasons why you might have someone a bit more like an adventurer, but NOW you get into games where the story is a LOT more like something that could be brewed up in Dungeon World or Torchbearer. That is, you got no choice, the world craps on you, and you have to respond. Something happens, you take what resources you've got, and you deal with it. Now, you can play D&D that way too, but here we are at the point where I hear people objecting that "stuff shouldn't constantly just happen to the PCs." Well, sure, that's nice, but its that or you're kind of a psycho, or maybe alternately you can play our 'Dungeon & Co.' style campaign where we mined the dungeon (totally the players idea, BTW, the GM thought we were the crazy ones until we explained it to him).
My point, ultimately, is that you cannot really say that you're role playing in any significant way if the characters are just these crazy murder hobos effectively. It just doesn't make sense. I remember thinking the same sort of thing about Traveller games, like "Why don't they just sell the Free Trader and like buy a mansion and retire right now before play even starts?" Sure, you can come up with some reasons why not, but you're playing a very narrow range of characters when you have to always do that!
