It's not a very productive idea to ask for a munitions-based ability which doesn't guarantee success warranted all conditions are right.Well, to be fair many other grenades aren't guaranteed success either. The basic infantry ones all tend to have a bit of scatter (including the Rifles' Mk II which frankly is probably why sometimes it actually doesn't one-shot squads these days ), the elite infantry ones do not have scatter.
Though yeah, I would not ask for the rifle grenade to have the possibility of missing entirely, it would not feel good. Vet 2 is mostly just the kinda dumb part of it and the rest is the infantry-bunching affecting every grenade (still didn't make the Molotovs feel good though ).