We older MMO players, myself included, usually like to identify ourselves as having come from the world of tabletop RPGs, and/or from the world of early, non-graphical RPGs – MUDs (Multi-User Dungeon) and all the hydra-headed acronym variants thereof.
For those accustomed only to computer, avatar-based gaming, a short definition might be in order, though it pays to bear in mind that not everyone agrees on what “role-playing” actually means; as with so many other things in gaming, definitions can vary according to who is giving them. Here's mine: Role-playing is the act of taking on the persona of a character who isn't the player, making decisions and taking actions based on that character's moral values, history and personality rather than on the player's. This doesn't necessarily mean there's no element of the player in the character; there often is. Personally, I find it difficult to play characters whose moral compass is too far off my own, but I had friends – very lovely people in real life – who could quite happily role-play the scabbiest dregs of humanity (and other races) and pull it off without offending or alarming everyone else around the table.
MMOs didn't grow out of a vacuum; in fact, they're the logical extension into a wider player base of tabletop games, MUDs, and the graphical single-player adventure RPGs that were already popular when the first MMOs were released. I can't remember exactly what my first single-player graphical RPG was, but I have fond memories of a number of SSI games based in AD&D worlds (when I could get them to run); and there was Baldur's Gate, which lots of people remember fondly, not to mention Planescape: Torment and a handful of others that stood above the rest.
When I was introduced to my first MMORPG, my friend told me it was like tabletop role-playing, only online and with other people; sort of like a MUSH but with pictures. And that's how I approached it. Creating a back-story and fleshing out my character's views and personality was part of the character creation process, even though there was no actual way to record that in-game. When I met people, I met them in-character and tried to interact with them as I would with other RP characters in tabletop games.
That lasted about a month. Coming across characters named Frenzied Monkey and Ur Mom (in Asheron's Call, names could be longer than a single word) was a bit of a kick in the shins to my role-playing, for starters. But it wasn't just the immersion that was at issue: I was also meeting and making friends with a whole slew of new people, most of whom I knew only online and only through the game, and I think it's almost impossible to meet new people you like without wanting to share some of yourself outside the game. If you're going to be playing with these same people day in, day out, for months or even years, it's natural to want to know them a little better than is possible through pure RP.
Ironically for a relatively hardcore tabletop role-player, I've always found it rather difficult to RP in online games. As a very visual person, I have problems with the fact that everything is already imagined for me: it's sort of like having read a book and then seeing the movie adaptation, where what you see doesn't always match up with what you'd imagined for yourself. I also have issues with the whole keyboard/screen disconnect between me and everyone else I'm RP-ing with. And then, of course, there's all the other role-players; there's nothing quite as demotivating as trying to RP with someone who thinks they know better than you what you should be doing and how you should be playing. (That's another irony right there, since it happens in games even in non-RP situations – there's always someone who knows better than you how you should play your class, and who isn't shy about telling you so, usually while playing their own for crap.)
As far as I'm concerned after a decade of experiencing it, massive online RP is at base nothing like tabletop RP used to be. Tabletop groups used to be static (for the most part), with people you knew or got to know and whom you saw in person every time you gathered to play. Online RP is often catch-as-catch-can with whoever you happen to run across. In fact, the most successful online RP experiences I know of involve a recreation of the static tabletop groups: people who know each other, if only online, who get together regularly, and who have had a chance to gel as a group. It's sort of like adventure-grouping: you can occasionally find some really cool PUGs, but for the most part you'll get a much smoother experience if you adventure with people you know and have worked with before.
In any case, these concerns are all entirely moot for the vast majority of today's online gaming population. Most gamers have never experienced pen'n'paper gaming and wouldn't even want to; many of them think it's downright weird, choosing to ignore the fact that playing a 7' orc wildly swinging a sword no normal person could even lift was also considered downright weird not so long ago, and is still considered a bit odd and possibly a bit suspicious by people who don't game. And then, of course, there's the whole gender issue with people playing opposite their own gender and the issues that seems to create for an even greater proportion of the gaming community; but my flame-retardant suit is at the cleaner's this week so we won't go there.
The RP in MMORPG is definitely not a given these days, and I'm not sure it ever really was anything but a minority interest, even though most of the initial MMO players were probably gamers, at least a decade ago. There's just too much else going on in MMOs, socially and experientially, to utterly enforce a rigid separation between who's onscreen and who's in the chair directing.
Nonetheless, I do think there's a case to be made for at least a dash of RP in one's MMOG-ing. It still jars me, though that may simply brand me as an ageing relic of the past, when people refer to their characters as “toons.” It's not the word per se, which is just a word, but rather the underlying assumption that whatever I'm playing is just a handy collection of pixels to project me into the game world; it's more like wearing a glove, which has no personality or desires of its own. I'm not sure how much personality or desires my own characters have, at least the characters I don't actively RP with, but I do still see a distinction between them and me, at least most of the time, and I don't consider them merely a vehicle for representing myself in Norrath or Azeroth or wherever I happen to be.
These are shared worlds and shared hallucinations we're taking part in – or are they? It's what they are for me, at least on some level, but I'm coming to the conclusion that for most gamers these days, the richness of these imaginary worlds and the effort that's gone into creating them is pretty much irrelevant. I'm also starting to realise that my own paradigm of what online gaming is probably isn't relevant to the current, evolved majority paradigm, especially with the rise of Facebook games and the like, which to me seem to be little more than social and marketing containers.
Paradigms will change over time and there's not that much that can be done about it; I certainly don't intend to stand on the shoreline Canuting at the new paradigm to turn itself back, since that would be at best a futile endeavour. Still, these non-RP or RP-lite games we play these days have a history and an evolutionary path that comes straight from RPGs, and it doesn't hurt to remember that now and then. There was a richness there, a particular kind of social interaction, that is extremely hard to find in online games these days.
So if you don't RP, at least don't hate on the people who do; they're carrying out a long tradition, even if it's one that may be dying out or that may have to adapt to the new ways in which we interact and play.