Part of the idea of tackle Dungeons and Dragons appeals to me, but at the same time, I think it would end up with a great deal more D&D players getting arrested and winding up on the news.
I wonder how many LARPers get arrested...
Anyway, I personally think that while it is certainly a response that comes up too quickly and too often, there are times for both DMs and players when they should consider leaving or asking a player to leave. For players, this is usually when it is clear that they will not enjoy the game, either because it simply isn't the style they like or because the DM is being "unreasonable" (that is, literally not listening to reason and logic). In these cases, where I can understand a player leaving, there is no compromise being allowed by the DM or the other players and it would become a tense and detrimental situation for the player to continue with this group as opposed to finding another group (or another game, if playing online). In the case of DMs, it is much the same. If the player has been approached about a problem (acting out grudges in-game, unacceptable social behavior, disrupting the campaign (various ways), ignoring the rules or restrictions (such as insisting on playing a class the DM has not allowed in the game; or the more extreme "cheating"), etc.) and has either completely refused to change or has only caused different problems in lieu of being denied his or her other disruptive behavior, or has said they would cease only to continue, then I can see it being justifiable to remove the player from the group.
To make an analogy, one of your "friends" comes up to you and punches you. You tell him to stop. He does it again. At this point, he's being a total dick. You tell him that he really needs to stop punching you or else you're going to have to call the cops to have him removed from the premises (lets say he's over at your house when he does that - you're the DM in this analogy anyway). He tells you, flat-out, "no," and punches you again. Are you justified in calling the cops to have him removed and/or to possibly file a restraining order and refuse to see him? I would say, "yes." Now, obviously, this might be a more serious case than merely being a dick about a game, but either way there is unwanted behavior and an unwillingness to cease said behavior. And in both cases it is detrimental to the DM (and other players involved - if they were present in this analogy, I guess he would be randomly hitting all of them throughout the evening or something as they hang out and watch football). There is no reason to put up with this (the fact that it might be psychotic behavior aside). It should not be required to pause and ask, "why are you punching me (us) in the face?," even as he continues to do it, allowing him to keep beating on you until you find out what the matter is (keeping him in the group, refusing to kick the player, even as he continues his behavior). There is a certain point when "kicking" a player from a group is acceptable.
