I don't really like restrictions, but I will admit id settle on a compromise of increased ammo or better projectile speed for throwing weapons, at the cost of being able to have melee weapons, shields or powerstrike with powerthrow or throwing weapons.
Although I can see how many would see this as a poor idea, but from what ive observed playing my melee characters, most of the anger at throwers stems from hybrid builds, some of whom do little more than spam throwing weapons with abandon until they run out and then take out their melee weapons and get most of their kills that way.