Items in this game are kind of lack luster.

[Xystic]

Finding gear like this is what gives people the drive to run dungeons over and over again for years.

You don't want to add these sort of things because you can pretty much build, character build's around that one item. Turning it from an okay item to overpowered quickly. Stats are easy to balance while RNG and special effects aren't. So many "X" swings will generate "X" amount of damage/procs. That "X" damage can be enhanced by certain classes with "Y" skill/stats and can be further enhanced by certain classes with "Z" gear which means X can be increased by an overwhelming number that could be much greater than a +1/+2 of anything. It would create such an imbalance in gear and classes.

Some have argued you could make it a static RNG or static base damage when proc'd that can't be amplified. Logically, thats the same as having +1/+2 of anything which is already static.