Permabanned
Yautja had to earn their plasmacaster by getting "blooded" ie: a rite of passage where they must hunt.
Some of them are "bad blood" therefore denied such weapons and are outcasts banished from the homeland. The Predator from this movie may have been one of these and possibly crafted his own weapons, but I think it's just a less evolved variant with not as good tech as the newer ones, but then you had the floating laser guided cluster bombs in this movie so....
Also it is considered among the least honourable weaponry the Yautja possess. Often, when faced with particularly worthy prey, a predator will discard his plasmacaster and rely instead on its more basic weapons.
Some of them are "bad blood" therefore denied such weapons and are outcasts banished from the homeland. The Predator from this movie may have been one of these and possibly crafted his own weapons, but I think it's just a less evolved variant with not as good tech as the newer ones, but then you had the floating laser guided cluster bombs in this movie so....
Also it is considered among the least honourable weaponry the Yautja possess. Often, when faced with particularly worthy prey, a predator will discard his plasmacaster and rely instead on its more basic weapons.