The only way I'd be content with a slight damage reduction is if the ammo capacity were increased. People can whine and complain about getting killed by a thrower, but 9 times out of 10 the thrower probably died pretty shortly after. I either go 3 stacks of jarrids (12 shots) and a shield, or three stacks and a sword, or two stacks a sword and a shield. This means that most of my ammo is expended within the first minute or two of combat, and in a large population server you become near useless unless you are super skilled and dont die while scavenging. If anyone comes at you with a higher level shield you waste most of your ammo right there. (Which is terrible considering thrown weapons text states that they're supposed to be very effective against shields) It costs most of your points to get up to the high levels of power throw required to get one hit kills, not to mention having next to no agility, so I'm very ineffective at melee and I can't run away from anyone. This is a problem if your weapons are slow and need to be used at closer range.
The people who are one shotting other players with thrown weapons are either hitting people with poor armor (who would get one shotted by a 2 hander or a crossbow anyway), or they have very high powerthrow which takes a lot to achieve and is only possible at high levels with points only in throwing abilities. More accuracy isn't needed. You can comp for that and do ok. It takes a lot of skill to use throwing weapons effectively and I don't really think they need altering in any way. The only problem is that everyone started using them because archery was nerfed. Maybe now that archery is more balanced people will go back to it. Continuing to nerf whatever the whiners pick of the week is wont ever make the game balanced.