I believe I am one of the very few enthusiasts of this bomb, but consider that:
-if you manage to hit one opponent with multiple shards then this bomb easily outmatches and radius-based bombs in terms of damage;
-the shards fly very, very far - way further than any pistol shots;
-SHOCK ELEMENT INCAPACITATES HEALERS (anyone thought about it? I did not - but I saw it and it does);
-your teammates see what is happening on battlefield (try two bombers with nitronomes - visual effects clouds the vision terribly);
-not as badass in some situations as sun shards, but if you are pure bomber, then you will appreciate that it works also against slimes, which are extremely easy to be hit with multiple shards (apart from quicksilvers);
-lichen colonies, Jelly King or Snarly - only two bits of experience and a bit of luck and they receive 8 times more damage (all 8 shards hit);
-finally - no knock back: if enemy is hit during attack animation, then they either fall or do nothing - no more situations when your mateys are hit by a monster that was swept next to them;
I thought I share my opinion here. As a side note: I use fiery atomizer + ionized rock salt and this combo is pretty good. My only regret is that there is no shard-based 5* bomb, but again: shard bombs can have their damage multiplied by 8, so the lack of 5* one is somewhat balanced.
Lack of 5* is what kills many items in this game from being used. If they're really balanced around 4*, then they're kind of OP considering how much cheaper it is to make them.