How is improved unit responsiveness from the last patch favoring rifle grenades? It means you have now more reaction time to escape. Units clumping up more affects all AoE weapons, why do Rifle grenades get singled out of this? It is those weapons that you cannot dodge at all that profit most from the last patch, namely stuff like tank shells.
Range, accesibility, animation.
It's not a problem with the RN per se rather than units hugging more now.
Edit:
PD: i wouldn't use a RN as a normal nade. The surprise factor is key here, so i wouldn't use it mid combat against another unit cause my opponent is pretty sure to be paying attention.