I've been reading a lot of posts about attunements, and I got to thinking about why exactly I like attunements.
The major reason is that I don't really like the gear game. I don't like making Best-In-Slot lists, or debating exactly what gear I need off what bosses. I just run stuff, and if something drops, I take it if it is better than what I have. My gear tends to evolve organically.
A good attunement chain or questline gives me a reason to run dungeons. It's something that I'm working towards, rather than my average gear ilevel hitting some minimum threshold. I do like beating every boss once, but after that you're just doing dungeons to prep for the next boss, or for social reasons.
I like having that extra goal to work towards.
Another element that was kind of similar were the old 8-piece class sets. I like collecting class sets, and don't mind running dungeons multiple times to get the set. I'm not really sure why this is different from running dungeons to get a pre-defined Best-In-Slot set, but it just is. Perhaps its the difference between making your character more powerful versus just collecting sets.
Perhaps it's just that Lightforge was so awesome. (Still in my bank!)
It just seems like in Wrath and Cataclysm, you ran 5-mans in order to make your character more powerful, so you could tackle raids. While in Vanilla and TBC, making your character more powerful was a secondary goal. You ran 5-mans to work on your attunements, or to collect your class set, or work on your class mount quest. And almost as a side-effect, your character got more powerful.