3 mostly unblockable dice is better than 4 blockable dice against high defense targets. While against a low agility ship more attacks would be better, against an imperial build where half their available ships have 3 agility it's quite good. Now against a rebel build where only one ship has 3 defense dice and 3 ships have a mere one it would be an almost total waste.
Quite clearly not a generalist weapon. It has a very clear purpose. If that purpose is too narrow for an all comers list so be it but it'll still see action in casual games.