The 100% return allowed to abuse this mechanic to transport energy via HEAL creeps, recycling them at the destination. And it seemed too much in general since they are "used" after all.
Dammit, you finally caught me
It's definitely expensive to do, but it's great for boosting up rooms that don't have terminals yet.
I don't really consider this "abuse", but I also have no problem with it being less efficient- this change makes sense to me, even if I am going to lose some of the benefits.