Not at all. The entire point of this line of discussion centers around limiting an implied personal right to reproduce for the good of society. A one-child policy might serve society's needs as a whole. A one-child policy that allows prospective parents to, say, flood the world with a supermajority of male children does not serve society's needs.
I think that gender selection via abortion is ok in the general sense, absent perverse incentives that cause society-crippling gender imbalances, but if those incentives exist and are abused, I can certainly understand a desire to make that illegal, while still allowing (and supporting) gender-blind abortion.
Even this thread is hopeful to me, a decade ago there wouldn't have been near as much disagreement about whether you have the right to burden society without limit.
Your elected government? Isn't that what you elected it for? Or just hold a referendum or something.
The "who decides" question is a problem here. It doesn't matter who, it only matters that the decision has to be made and then carried out. The coordination has to arise or be enforced, but happen the coordination must. What you're implying by asking this question has many names. In politics, it's "total anarchy". In biology, it's "cancer". In infrastructure projects, it's called NIMBYsm. Imagine trying to run a large company with the rule "we're all equal, who gets to decide?" - how long would it survive?
Like it or not, Earth will have to have a "top management" layer. Run it top-down, run it co-op style, whatever - but after some size, you can no longer ignore the looming coordination problems and their deadly consequences.
Yes, as with everything, there are failure modes. Coercive abortion and gender selection happen mostly because of misalignment between "one child rule" and the economics, so the people selfishly prefer to spawn an offspring that will give better economic payoff. But incentive structures we can manage. We could manage it better if we stopped just asking "who gets to decide?" and instead picked someone to decide.
Also, the only problem with "coercive abortion" is the "coercive" part; if you believe that abortion is ok, then gender selection via abortion is also ok. If you don't believe gender selection via abortion is ok, then you also must disagree with general abortion as a practice.
EDIT:
Also2, we have a "who gets to decide?" problem when it comes to inconvenience ourselves and spawn less children, but we do not have that problem when it comes to decide who to bomb the living shit out of, killing their children, along with parents, grandparents, livestock and future. Strange, isn't it?