I think people confuse Role and Roll in Role Play.
Role means...a part in an enactment, such as a character in a theater.
Roll means...to tumble...such as tossing a die.
Much of Role Play in games has been reduced to Roll Play. Random number crunching based off of statistics. True Role Play involves immersing one's self in a character or at least learning his part in the situations he is presented with within the Role Play.
Role Play Gaming is often credited to Dungeons and Dragons. Interestingly, Dungeons and Dragons has many elements of Role Play and Roll Play. However, the Roll Play aspect has a Role Play purpose...While pretending to be a different person in a different world, you have to know how your character differs from yourself. Thus, you might Role Play a character that is smarter than you. So how do you play a character smarter than you? If you want to try to do something smart, you have a stat that allows you to know how smart your character is, and using that stat, your character could pass a skill check that lets her do something smart. The introduction of stats was a great blessing to Role Play games, but it seems to have been blown out of proportions and lost some of its purpose in most games.
A Roll Play game can be fun. I think every MMORPG fits into this category by their very natures. You cannot immerse yourself into the MMORPG environment or character because MMORPG's don't let you make decisions with any impact on the environment. It's all about finding stuff, killing stuff, and collecting stuff. This is fun, and their worlds can be very glorious and alive because of the art and populations.
It's hard to find great Role Play out there, though. I have immersed myself in Neverwinter Nights as a Dungeon Master. Several skilled Role-Players join my games regularly.
I have found they enjoy simple adventures not because of the world I created, but because they enjoy interacting in-character with each other. As they play together from week to week, their characters are developing...Not just personally, but also they seem to develop relationships. One character will start to anticipate the actions of the other characters. There's something built there that's not a statistic, and if it were reduced to one, it would lose everything that's enjoyable about it.
Role Play also has Consequences which are not stat-related. The best consequences are founded on players' decisions. As Dungeon Master, I have the chance to place characters into difficult situations. The classic example is that of Spiderman. The Goblin kidnaps Spiderman's girlfriend, Mary Jane, and also captures a busload of elementary children. Now Spiderman faces a difficult choice. He can rescue Mary Jane, or the Children, or he can attempt to rescue both. The attempt has a chance of failure, but the other choices represent a type of moral dilemna.
In a Role Play game, a choice like Spiderman's would have permanent consequences. The loss of the children might cause feelings of remorse. He may face outside consequences, such as hatred by the community. The loss of Mary Jane would have been obvious by the lack of her presence.
Can you imagine a choice like this in a game like World of Warcraft? The game's design doesn't allow for anything like it. The whole world resets itself for the next player. There's no consequence. It's just players going through the quests.
There are serious limitations to the way MMORPG's are designed these days. And it's obvious that the industry is stuck on it. For players to experience something truly fantastic, someone needs to find a way to make this work. Sure, there's always a place for a simple, fun, fight-the-monsters and get rewards gaming experience. But there is certainly also a group of people out there...and I bet it's bigger than people give it credit...that are craving for a more meaningful experience in their online games. Perhaps the next big hit in MMORPG's will be from the studio that distinguishes the lack of Role Play, not Roll Play, in Online Games.