I've been melee for 4 generations, now I have 3 proficiencies at generation 5. What are they you might ask? 1h, 2h, and THROWING. For this, I have 72 or so WPF. 85 in the 1h/2h. I also have to invest 3 points of power throw into it. Weapon proficiencies work for Throwing, and are required for accuracy. I could shoot a bow without proficiency on this character by replacing throwing with it. Will it be like an archer? no, but it's still a weapon. I'll do damage, but not be too accurate.
Anyway, higher end throwing weapons have only 2 weapons per slot, but still people go pure throwing and can get 6-8 kills easy with those weapons. They're just annoying because they 1-hit constantly. It also takes 7 power throw in order to 1-hit, along with proficiency, which takes a while to get. But just as HA goes, that's no excuse. I would only justify lowering the power to HIGHER-END throwing weapons.
EDIT: Not very well put together, but my point is in there somewhere.