The other day I rolled a monk, leveled him to 15, then deleted him. I didn't do it because I didn't like him, or monks in general - I did it because the only reason I rolled and leveled him in the first place was to experience the Wandering Isle experience again.
Sometimes I get mono-focused on the endgame. It's understandable that it would happen - I like to raid, I'm in a raiding guild, it's what I do. But it misses that there's more to the game than raiding, more than the level 90 experience of getting ready to do stuff. You're always gearing at 90 - getting better gear to run content to get better gear to run other content until you eventually kill the hardest content you possibly can. There's something to be said for the simplicity of leveling - sure, there's gear, but you get it and get rid of it at the drop of a hat (sometimes literally, hats do drop and you do put them on and then get a new hat to drop and put that one on) - it's less important. Or at least it feels less all-important.
So sometimes I roll an alt of a class I'd never play, take it for a 10 to 20 level spin, then delete it. It's fun. It reminds me of how uncomplicated the game can be, if you let it.