Ppl "prefer" l2off cuz it's "less bugged" - at least they think like that, since they don't know anything about off or java packs. So, basically they prefer l2off files, cuz of "less bugs" and better "balance". :P
It's because everyone wants to be an admin/gm/'developer' without any knowledge (for ex: they dont know how to apply a patch) about java and so, there is tons of servers based on java files with such admins. There is a small or bigger problem and boom, server goes down cuz of that, it's closed after 2 days or a week at best.
In this way l2off is bettah. Thanks to all wannabes :D