How fast do you think you could run 100 meters?
Now, I don't know much about Track and Field, but I'm pretty sure you could run 100m in a little over 20 seconds. The world record is just under 10 seconds for men and just over 10 seconds for women.
Again, I don't know much regarding track, but I'm willing to bet that someone capable of matching or exceeding the world record trains tens of thousands of hours more than you or I do. All of that time, all of those thousands of hours of training, leads to cutting the time in half, and I bet the first 6 seconds off that time can be achieved within the first thousand hours.
You see, human skill levels are logarithmic. The return on the investment of time training grows smaller the more you train.
Now imagine your WoW character. If the skill level of your WoW character was logarithmic, a level 80 character would be only marginally better than a level 70 character, despite the fact that it probably took most people longer to go from 70 to 80 than 1 to 40. How many level 10 characters do you think it takes to down a single level 80 character? Maybe an infinite number.
The fact is, in almost all RPGs, the advancement is exactly the opposite: exponential. Experience required to level up increases exponentially, but so does experience gained, so your power level increase to time spent ratio goes up the longer you play.
My hunch is that this is done to give games a wider appeal. The bread and butter of RPGs, at least to some degree, has always been repetition. If you can't fight things in at least a somewhat similar fashion, it's difficult to feel like you've advanced at all, and the feeling of advancement is what RPGs bank on to counteract the somewhat repetitive nature of their play.
As I play through a game, and get more and more accustomed to its play style, I need additional reinforcement from other sources to overcome the diminishing returns of the novelty of the system. In RPGs, the main supplanting reinforcement is the feeling of character advancement (combined with the sometimes heavy reinforcement of unfolding narrative).
In fact, mastery plays a large part in many people's enjoyment of games, (don't worry, I won't throw in one of those tacky blog quizzes about “What kind of gamer are you?”) but there's an important distinction, I think, between games in which your advance through skill mastery alone, and games where you advance through a combination of skill mastery and character advancement. Sure, almost every game has some amount of character advancement: your character is more powerful in Doom when you have the chaingun than when you only had the pistol, but for the most part, any advance you make in that game is based on your own skill level increasing.
Not so with RPGs. Truthfully, I'm not sure I was any “better” at Final Fantasy 7 when I beat it than when I started it. It's not exactly a terribly skill intensive game. In fact, the term “RPG”, has come to describe games in which a character's numerical advancement is a large part of progression through the game, despite the fact that there's absolutely no connection between the terms. In Half Life, you play the role of Gordon Freeman, but that doesn't seem to mean anything anymore.
The term RPG, and the idea of critical hits (as I mentioned in the last post), I think, are just more subtle ways in which very specific gaming tropes get generalized to form a gaming subculture, which is a point of great fascination to me. I'll let you know when I get my degree in cultural anthropology so I can sound like I know what I'm talking about.