The No Numbers Concept
The fact that a traditional RPG is essentially a numerical simulation has spawned a number of very annoying trends in player behavior. Most of these types of behavior can be subsumed under the term "numbercrunching." Also called "min/maxing," numbercrunching largely involves the study of the game’s numerical systems and figuring out how to use it to the player’s best advantage. Therefore, becoming a better fighter is more a matter of allocating your points appropriately, instead of logical considerations like developing advanced tactics, using terrain effectively, and personal bravery. The player character is reduced to little more than a spreadsheet, and players become obsessed with watching their numbers increase. Unfortunately, the game system eventually evolves to accomodate this sort of player with provisos like high-xp farming areas, repeatable activites to raise use-based skills efficiently with a macro, etc.
It is my firm belief that the axiom "most players are self-centered bastards who will ruin other players’ experience at the drop of a hat" is greatly exacerbated by this numerical obsession. Why do players steal kills from other players? Because doing so will help their numbers increase. Why do players exploit bugs to kill monsters (or players) with relative ease? Because doing so will increase their numbers. Why do players use cheats and plugins that give them unfair advantages in the game world? You get the picture. Sure, some of this activity stems from a desire to simply ruin the game for other players, and some people gain enjoyment from this, but there is no way to deal effectively with this sort of player except to quickly identify and remove him from your game.
Now consider the effects of a use-based skill system where the numbers are effectively hidden from the player. This means he cannot see his exact strength or hit points, he does not know that his sword does X amount of damage per hit, and wounds are represented graphically only, either status bars, hit location indicators, or ideally an actual change in texmaps reflecting damage to specific body parts. The player will have a pretty good idea that he is decent with an axe, a novice at archery, and completely unskilled at alchemy, but he doesn’t have a number to refer to as his "skill." Once in a while, he may receive a system message telling him that he has learned something new about pottery, but these messages should be unreliable and ambiguous. He may even be able to compete for titles in various contests of skill, but this is only an indicator of prowess, not a measurable figure that you can watch increase as you fight your eight millionth orc. Sure, there are players who will still go camp the goblins for "skill," but he can’t really be sure it’s doing him all that much good, and if the designer has been building his system holistically, it’s not.
What happens now is that with visible numbers unavailable for scorekeeping purposes, plyers become less interested in keeping score. This puts more pressure on the developer to make sure there is plenty of interesting stuff to do for the player, once the possibility of spreadsheet tweaking is removed. Such a system requres more diligence and work on the part of the developer, in many ways, but the payoff is immense. With numbers removed, your environment becomes more immersive. With spreadsheets removed, you remove a great source of annoying player behavior. And you may be able to reclaim some of that market that abandoned computer-based gaming for more logical paper systems.