As they add content an mobs with good AI and AoE, smart melee players will know how/wy to use the ranged weapons.
I've seen plenty doing it anyway and I use them when I'm levelling as well:
Mob starts a tp attack, I more to range if needed and throw weapons at it till it gets back to me.

They are a secondary attack though, so no i dont feel they should be brought in line with primary attacks.
Hmm... but a class/job with bombs or something might be interesting (Balthier style in FFXII)