In Diablo 2 each monster had specific resistances, and even immunity against Cold/Fire/Lightning/Poison. And you had to choose your skills and weapons to do the correct damage types.What's wrong with weapon damage?
In Diablo 3 they dropped all this and now it really just comes down to the bigger number is the better one. Type doesn't matter. I mean the way it ended up the Holy, Poison, Cold, ect, ect, might as well be plus gooder since in the end it really doesn't exist or matter.