Which warlock bulid are we talking about ?
The One Proc build, OP mentioned in another thread he/she was using it, and since it is the highest dmg build for Warlock, it is the build i always recommend it for anyone that wants to do Raid content as a Warlock.
Even if you go melee warlock you still want to use the 3 passive procs since they are what deals the most damage out of the warlock skills, so there really is not much difference between a melee and ranged Warlock, as a Melee lock you use a melee as your main spammable, and as ranged you use a ranged as your main spammable, the damage difference tho is huge.
I suppose you could say there isnt much viable options due to some abilities not being as useful as others. Also, most "on kill" abilities for classes are useless, there are a FEW that can be useful, but most are just useless. Tho most games usualy end up with their clases having only 1-2 builds that are hailed as "the best" anyway, and its really hard to make every ability for every class have equal usefulness.