If you look in the sidebar of the article, its summary was:
> Is sperm donating a worthwhile form of positive eugenics?
So yes, the author is well aware that he's talking about eugenics, and plainly isn't bothered by it. The problem with eugenics has never been the concept per se, but rather, the methods used to achieve it. Sperm donation is wholly voluntary.
Maybe, but voluntarism is only part of the moral equation.
So-called genetic "designer babies" are widely considered morally problematic but that process is totally voluntary; and in general eugenics provides an echo-chamber for certain discriminatory beliefs. In a very strong way what we're talking about is capitalism, which does the same thing -- unregulated markets adapt to whatever discrimination allows them to have more customers.
So I agree with the comment a couple levels above -- there is a strong batch of ethical concerns here beyond just "there are kids out there who biologically trace you as their father/mother" and it's a bit of a pity that those concerns were not strongly addressed.
I think what we have here is a case of status quo bias -- new things get subjected to more intense ethical scrutiny because they're new. Selective breeding of humans has been around for as long as there have been humans; it's what people do when they choose a mate. Evolutionarily, this is simply a matter of trying to choose the most advantageous genes to mix with yours, to maximize the expected propagation of your own genes. In practice, it is a eugenics program on a vast scale, and nobody seems to have a problem with it, despite the fact that it "provides an echo-chamber for certain discriminatory beliefs" and can lead to inbreeding if you're reckless.
All that sperm banks do is amplify this selection.