You know that it's normal thing when you app. solo or quick join? Aslo there is a system that kick afk/bad players, it's called forming your own group.
AFKing was always an issue, even at the height of Aion's popularity so I really don't think it has any effect on much in the long run, other then potentially ruining your quick entry, but then again if you cared for the instance you wouldn't go in via quick entry.