Bartle first explores the differences between "game", "simulation", "sport", "hobby", etc. He concludes that virtual worlds are not games per se, but they are "places". Places where you can conduct game-like activities. Sort of like Las Vegas where you can play poker, but Las Vegas is not a game; it's a place.

"When you play a game and you know the rules and something happens within those rules, you just have to accept it. You may not like it that the other team scored the touchdown, but you knew it was a possibility. All you can do is try harder. This would be a fine analogy if virtual worlds were games. They're not, though: They're places. Some activities may be game-like, but not everything is. When players treat non-game behavior like it was a game, this can have a nasty impact on other people in real life.

In normal computer games, you can do anything that the code allows you to. This is not an attitude that extends to virtual worlds, though. Most of the time it's a good rule of thumb, but sometimes the virtual world lets you do things that you shouldn't. As a trivial example, they aren't coded to prevent your saying things that in real life would constitute verbal abuse."

He further says that, basically, it's okay to do things that the virtual world is "about". In Carrion Fields' instance, the game is about killing, so you can expect that your character be killed and if you feel emotional trauma over it, it's your problem and not the world's because you were warned that this is a major aspect of the world.

So in this, Bartle's work supports your theory. CF's very design boasts "actual setbacks when you die" and "real villains that can win" (sorry, I don't remember the precise wording) so guess what, the game is about harsh struggle and thus we should agree to not let being killed/full-looted affect our emotions.

I would still argue, though, that not full looting doesn't necessarily mean breach of RP for "sportsmanship". Given the peculiarities of how death works in CF, I may want my enemy to actually get back on his feet faster, so he'd fight me again and get killed more often.