Huh? What's strange about that? "Sanctity of life" is a make-believe reason; it's superstition. An embryo isn't a person. Quality of life of people in the future is a real reason; it's utilitarianism.
He really didn't. You can't suppress sex-selection abortions by prohibiting them -- people who want one will just lie about their reasons. What you can do to suppress sex-selection abortions is prohibit medical clinics from telling parents whether they're going to have boys or girls. So actually he put the future contentment of men on the list of reasons to restrict information flow."Reasonable" requires a reason. You just put the future contentment of men on the list of reasons to prohibit abortions.
If that works for you, fine. It's simple to drawn the line around the definition of a person to not include embryos. A line is just a line and it can be put anywhere one pleases. This allows people who are otherwise opposed to killing to accept the idea of abortion and still feel philosophically consistent.
One would assume gender selection abortions would only take place once the gender of the non-person embryo is determined. It still comes down to a reason to deny a woman a choice in the matter, and that reason is, as Loren states, "Whereas the large numbers of men who can't find wives cause very real social problems."
So, we have an reason for having an abortion which is not ethical, because men have a right to a fair shot at sexual happiness. If there is another way to say, let me hear you.