Given the amount of love, energy, and attention it takes to raise a kid, I don't see why I should care how selective somebody else wants to be.
Character, beauty, love, sacrifice. Every one of these involves pain and it makes life worth living. You can't avoid pain, so you might as well engage it in service of those you hold dear.
You should very much care about society wielding a sword like this, because historically we do not wield it well.
It's easy to hand wave the question of pain away, but much wiser men than you and I have arrived at very different conclusions than you suggest.
It's very easy to demand or promote sacrifices you expect other people to make. But I don't find that to be very empathetic.
I've already seen how society is when we shame and hand-wring about the personal decisions others make, and it's not one I want for my kids. At some point you need to be satisfied with your own decisions and then let other people make theirs.
I can be both satisfied with my decisions and still wish better for my neighbor; these are not mutually exclusive.
I am not saying, don't choose between embryos. I'm saying, be careful because it's a slippery slope and not a slide you want to ride.
Eliminating Down syndrome and cystic fibrosis, for example, seems not only reasonable but a moral imperative.