Based on the comments so far I've concluded three things. Throwing weapons are good for...
1) Leveling at low levels.
-- Quite frankly there are a million things you can do at
low levels to increase leveling speed. Personally, when leveling a caster I would rather spam dmg spells for 2x XP, and then go sleep at the nearest Inn, because for most low level leveling grounds an Inn is less than 1 tick away. As a fighter, get some decent armor and you won't take damage, low levels are already a joke enough for fighters.
Also, I just spent a good amount of time with my current caster enchanting a whole slew of daggers and attempting to use them solo or along side my damage spells for leveling. I found it a ridiculous waste of my time. I hit maybe 75% of the time, and even with 15 daggers I wasn't able to kill anything without also finishing them off with magic. I'll admit some things contributed to this: My low str(although I did mod it close to max for this testing), not having dagger (mastered). Even those two things aside by throwing daggers at my opponent all I did was give them a weapon to wield and beat the [REDACTED] out of either myself, or my pet, with. The only way I could see throwing weapons being viable during mid-level leveling is for sorcerers to polymorph into a fire elemental and be front row...Also you would have to be careful not to enchant the daggers above your current level or else it defeats the purpose of the polymorph. Even still, I doubt it would be as rewarding as just spamming magic missile from behind one of several store bought pets.
2) Throwing spears good for PK.
-- Okay sure, one viable use for throwing weapons, although only really useful if your class can use spears.
3) Poison/plague a dagger and throw.
-- Yeah...necro's have a lot better things to do than this. Not to mention the chances of a throw from a necromancer missing are fairly high, unless you had someone take the time to enchant the stash of daggers you keep around for this purpose.
So that leaves us with
Throwing spears are good in PK as a viable use for throwing weapons to the playerbase. That seems like an awfully small portion of the game to me. Considering only two classes that get the 'spear' skill also get 'skirmish' That means two classes in the entire game have
one use for throwing weapons.
I would really like to see throwing weapons become a bigger part of the game, I think it would add a lot of diversity to certain classes and give them the opportunity to play other roles in their groups/factions.