I am saying that if we condemn such behavior in all cases (even when neutrality is violated in our favour) we'll reduce the situations when that second strategy

I am saying that if we condemn such behavior in all cases (even when neutrality is violated in our favour) we'll reduce the situations when that second strategy becomes profitable, and that will benefit everyone. We don't even need a very large percentage of people for this, even a relatively small group that always supports neutrality will be enough to keep the market neutral.