Oh, you died? Don't worry, in this world, death is temporary: you must wander the lands as a ghost for a while, but if you're able to find your old body, magical forces will enable you to re-enter it and come back to life. No permanent damage done, and no existential disillusion! It's all very well explained, you see. What's that? You want to chase someone into that cave, the one with the swirling
airy entrance? You can't, I'm afraid. He'll be in his own private instance. Yeah, you see, the server clones the cave multiple times for every player or group that wants to enter, so you don't get in each others way. Erm, I mean, the magical forces.. they cause a, um, a splice in the ether.. and.. er.....
Take death. Whether it's fully explained or not, you very rarely encounter an MMO where you just respawn upon death. You're never just plopped back to the start of the dungeon like you've reloaded a saved game. There's always some (flimsy or not) explanation as to why YOU CANT DIE, whether it's because you're some kind of mighty immortal (Eve Online, Rift) or because the
world has advanced magic/technology that prevents it (Anarchy Online).
Developers spend a lot of money on creating a game that feels like a world. This is done through building detailed lore, beautiful art direction and musical backing, through in-game storytelling and in the very structuring of its mechanics. Nobody would play The MMORPG, the latest and most generic MMO including 6 classes (class1, class2, class3...), 10 races (race1, race2...) each with unique abilities (class1_spell1, class1_spell2...) and zero filler text.
I mean, that's what the skeleton of a WoW-style MMO is, anyway. But until its fleshed out with colourful and engrossing detail, it's not exactly going to get many players.
Why, and how, then, have developers come to happily leave bones showing? Why is it completely accepted that instances need no in-game explanation? Surely it's worth explaining why you'll never find the person you chased into the swirly-aired cave? Or the fact you can be standing anywhere in the world, and all of a sudden be transported to a battleground to do battle with people who don't even share the same world as you, before being shot back to where you were originally? Or why you're standing in exactly the same room as your friend that you were hunting with earlier, yet you can't see him?
Some games have made more effort than others. For instance, in Anarchy Online and Neocron, you entered your instanced flat by entering a lift in a big appartment building, and you just don't see the bit where you move to your individual room. Meanwhile in Everquest 2 you would zone into your room by entering its specific door, in-and-out of which would be tens of other players. Huh?
Sometimes it creates more serious gameplay repurcussions, such as in Age of Conan where outdoor areas were heavily instanced. Not only did this mean you might be talking to a friend who's supposedly standing right next to you but isn't, but on pvp servers resulted in the ridiculous game of chasing people through the different instances, with players inexplicably fleeing to unexplained parallel universes.
I've always had a problem with instances, and how they destroy many aspects of MMORPGs that I consider important. But the way developers chuck them into games with absolutely no concern for continuity, and that players have just come to accept their functional but inexplicable nature, really hints at how badly the MMO genre needs a good fucking shake about.