Unbalancing the NON-PvP related rewards (PvP related would be PvP xp and Wolf Marks) would be a HUGE mistake and kill off PvP participation. Enforcing a minimum level of activity would be a good idea but is very hard to implement beyond the afk timer that already exists. Also, this problem must be more prevalent on data centers other than Primal as I have seen very few people actually AFK at least on my teams.