Gameplay-wise, bladelings are way too tanky and are a pain in the ass to fight as a result of not just their very high resistances (forcing people to switch to either armor-piercing options or alternate damage sources that they are not resistant to like energy, or bio if you're doing the invasion quest) and decent health, but also the immunity to criticals when they're one of the main ways someone improves their damage because of the slow scaling of base damage (having 100 effective skill merely multiplies the damage by 1.7x). With the W2C nerf reducing how much resistance is ignored (from 26% Bladeling resistance to 41-48%) it got even worse, crossbowers still don't have a reliable option and for psi the only ability that reliably does any damage before Plasma Beam is Temporal Distortion to a single target (that might spread to more if you got the feat).
Lore-wise, I imagine that actually breaching the rock as a result of the armor-piercing attack should hit some sort of vital.