Closet eugenicist attacks a sperm bank

I just listened to a rebroadcast of this podcast, including David Plotz saying this:

My father, who was suddenly burst out with anger that it was the kind of project that Hitler would do trying to create super children. [at 30:05] ...

I remembered my father's rage, and I decided to dig into this sperm bank.

For background, you can read his Slate article or his book.

For Jews like the Plotzes, getting angry and making a comparison to Hitler is about as bad as it gets. Plotz's wife, Hanna Rosin, was born in Israel, and is best known for writing an essay on "the end of men".

I am wondering what the Plotzes were so agitated about. The sperm bank in question was just like all the other sperm banks today, and they are not particularly controversial. The story involved a couple that wanted a child, and they used a sperm donor because the husband was infertile.

There are sperm banks in Israel, so the concept is acceptable to most Jews. But somehow Jewish leftists hate the idea of non-Jews having some choice about using a sperm bank.

Looking for an explanation on the web, I find this:

Glad's controversial thesis: since the 1960s, a prominent group of Jewish public intellectuals has been systematically and unscrupulously campaigning to discredit eugenics — but, in a great paradox, other Jewish intellectuals, and Zionists, have been actively interested in eugenic principles, both historically and currently, to secure the posterity — health and wellbeing — of Jews. Collectively, it amounts to a case of Do As I Say — Not As I Do.

Jews have a long history of supporting eugenics among Jews, according to this and this, and opposing it for non-Jews.

This would suggest that Plotz is some sort of closet eugenicist. Is there a better explanation?