If you haven't seen the movie Gattica, you really should.

The issue comes down to the misalignment of what's best for an individual, and society.

Individually, genetically pre-screening embryos (or even altering them) to maximize a kids chance for success is a no brainer. Of course the vast majority of people would do that for their kids if they could.

But that bumps up against the problem of then creating an extremely homogeneous society. They tend to be brittle and stagnant. Deversity is strength for large populations.

Since individuals will absolutely embrace eugenics given the chance, it needs to be strictly regulated and stigmatized by the government. But democratic governments are (ideally) responsible to the will of the people. Given that, unpopular regulations are unlikely.

What happens, happens.
All we can do, is all we can do.