From what I can tell, all they did was extend the blast radius from three to four to match Nitronome and add stun to both. Damage rates seem to be the same, stun is still broken, and the increased range is not a significant incentive. These two alternative lines, more so for Big Angry, are essentially tsunamis compared to normal wave currents; the tsunami has more power, but the other waves have more speed and height. One has the power to squish you into liquids, the other is big and rolls in fast but is less powerful in water pressure. Which is more threatening?
The main appeal to the old Big Angry and to a lesser extent Irontech was more damage per hit and knockback. Big Angry has a big model but the blast radius was smaller. The explosive strength of the bomb was condensed so targets caught in its blast would be damaged more, but since we fight in open areas that would not make sense; how does something condense the explosion if there is nothing to condense it? Try filling a balloon with water until it pops when the balloon is a barrel. This may have been why they increased the range instead of the damage, though with more damage Big Angry would slowly creep towards being the single target fan favorite for bombers since Three Rings took the old shard bomb mechanic away. Irontech can still be the middle ground between Big Angry and Nitronome, but Big Angry is supposed to be more bang for the buck while Nitronome allows users more mobility and speed. Speed or brute force. With a larger blast radius on Big Angry its animation was also increased, meaning laggier explosions and more deterrents for a bomb which could be far more useful than it has become. Bombs are allegedly designed for area of effect, swords for melee, and guns for range, but there are distinct deviations from this triangle for swords and guns. No one is saying to have a bomb with a normal attack which damages independently. No one is saying we should have bombs which are specifically designed to fire projectiles. Some say there should be a bomb option for single/few targets to deal more damage to less targets, which the old shard bomb mechanic did with multi-impact effects. Those are hardcore bombers. If I were to have changed Big Angry it would have been to decrease the blast radius from three to two spaces and increase the damage so it does more against one to three targets than Nitronome would but less with more targets. More damage against less enemies. Less damage against more enemies. Irontech can be in that weird middle ground or have a completely different bomb mechanic, though the latter is unlikely.
Why was there no change to Deconstructer line? Ask the same for Spur line. And Vanquisher. And Chroma lines. And Jelly line. And Magnus lines. And Plate lines. In fact, there are far too many underpowered equipment items.
But here, I'm in full agreement. Bring back the old shards! (Or at least make these new ones half-decent...)