That was me back in the day. During the issue with RWZ's release (6?), Castle changed RB from being ally- to mob-targeted and gave it a 10X damage increase (not joking), but kept the KB magnitude the same. Its damage and animation were the same as Neutron Bomb, but its recharge was 2X as long. The goal was clearly to make it an "always take" power instead of one that was easily skipped. If a squishy was in trouble, Repulsion Field and Force Bolt were there with Force Bubble around if you wanted to clear a bunch of mobs. There were a some people who loved the power, but I did have some success in getting people to call it Repulsion Turd.
Specifically, RWZ had chain link fences -- you could KB mobs through them, rendering the mobs untargettable. Yuck. And some builds, like FF / Rad, always had problems with KB playing nice with the PBAoE, the cone, and the heavy hitting, but short ranged, ST attack (apologies, been a long time, names slipping away). So ... Castle lowered the KB magnitude on my feedback to make sure it would always be useful to every build. You could get much of the KB back by slotting KB enhancers. Remember, this was before inventions.
With the KB > KD proc, this change should be rolled back. for maximum versatility.