And rockbiters damage reduction makes it a fair swap.
Elemental blast has too much downtime in pvp for enhance.
The only other option being primal elementalist, which Isn't good because the earth elementals support outweighs the fire elementals damage in most cases, but only one can be out at a time, so really it's like Unleashed fury but lasts much longer, can only be used once, only 1 at a time with 5 min cd each, and is also susceptible to damage and cc.
Also, choosing PE means very little uptime on melee ranged ability's.
So go ahead and buff the PE talent damage another 20%, it still won't beat UF in pvp.
Just providing awareness.