I really don't know where you're looking, since there are some 500 users online each day and things are being released at least every week or so. I don't think that qualifies as "dead" (see: eAthena).
On the other hand, you're right that interest in RO has decreased; most of the old players/developers have moved on, and 2D MMOs aren't exactly in demand anymore. But your server more likely isn't attracting players because people expect more innovative ideas than before (given that all the creative events, etc. are now pretty much standard), and what attracted people years ago isn't necessarily what people want to see now.