I've always supported Soul Gems having more use in game - sure, not everyone has a caster, but it would give the spell more reason for existing, and also ensure player-to-player interaction, as an MMO should be played.
I wouldn't mind Wizards and Sorcs being sought out for Trapped Souls, Rogues being sought out for Trap Parts (trap parts could be used in Cannith Crafting, think on it!), etc. I wouldn't mind if the Bard Skill song gave you an extra 10% on crafting - bards would be on hire to help assist people.
This actually assist cooperative gameplay, rather than the 10.1 mistaken implementations that would work to destroy it.
Also, to play Devil's Advocate - anyone can use an Epic Souleater to get Soul Gems. If they really really really didn't want to make friends to the point that someone could provide them the Soul Gems, and also did not want to raid, that is their other option.
That... or just roll a dang caster. They're fun!