I've had this happen to me once, although it was Maelstrom camping Flames spawn point.

There was a mechanic in a couple other online games I've played where they placed NPC's around that would chase/kill off anyone that tried to get too close to their base. I think that'd fix this problem. Even if they do camp just before said NPC's, at least now people can run backwards towards the NPC's for protection while still being able to attack with ranged skills.