Insulating the commission means you won't allow a party to seize power and then cement it with gerrymandering, which is self-reinforcing. Cutting that loop mean

Insulating the commission means you won't allow a party to seize power and then cement it with gerrymandering, which is self-reinforcing. Cutting that loop means the commission can swing back and forth more easily and has the potential to even out. It can't possibly be worse than partisan gerrymandering.