Mob hunting on Beta definitely needs another incentive given that beacons exist.*
The incentive, however, needs to be something unique to killing an NPC on Beta.
Maybe something like a dog tag where a certain number of dog tags (think lots) can be exchanged in the Syndicate store for special ammo, special gear or even special robots or ... well, I think we all know the Syndicate store has huge potential but that's covered in other threads.
*Personally I'd get rid of beacons completely - at the very least get rid of them from SAP loot and up their SS price.