Because I think it deserves a shot on another cool website.
Oh, people always want to write fan fiction of their favorite artistic creations. Turns out code is no exception. :P
Being an admin is a huge responsibility, even if it's just a little online corner for you and your friends. Rewarding, too (except when things go south). You'll have to walk on eggs, both from a social and technical standpoint, and you'll break things anyway. But the gratitude of people when you manage to genuinely help them is worth the trouble.
Try it! Even just founding a DeviantArt group or some such will give you a taste. Just don't do it only to have total dominion over a playground, because then it gets boring fast, and you won't have anyone else to blame.