Yes, you're correct, I think we shouldn't discuss this as a gender issue.
IMO you're mistaking correlation for causation. As you say yourself, changing current salary setup would affect both women and men. This is not gender issue and this should be discussed on other points than gender. Making it about gender is counter productive.
Looking at this form economical perspective, as long as we don't have objective way to measure programmer's productivity, I don't think we can get away from salary negotiations.
IMO you're mistaking correlation for causation. As you say yourself, changing current salary setup would affect both women and men. This is not gender issue and this should be discussed on other points than gender. Making it about gender is counter productive.
Looking at this form economical perspective, as long as we don't have objective way to measure programmer's productivity, I don't think we can get away from salary negotiations.