JP gear is 371, and therefor better as EVERY single loot in random dungeons (outside trinkets).
Going in a random overgeared is called optimisation in my books, OP is just dumb asking blue PVE geared. Player quality isn't tied to his gear, someone doing crap in PVP gear will also do crap in PVE gear (my full PVP hunter alt does 18-20k in randoms, I won't do better in 346 blue).