Earlier quoted context omitted.
Eugenics and Phrenology were very relevant at the time and used as a scientific basis to justify many attrocities. It's important to remember that science evolves, and what we "know" to be part of scientific knowledge today might be debunked in the future. Specially with the state of peer review in the social sciences my feeling is many things that are said to be scientific fact today will be proven wrong later, incl…
Pseudoscience like eugenics is just feelings packaged as science.
The former is a question of fact ("is this possible?") though often with a bunch of unspoken subquestions ("can we do this change without causing incidental genetic changes or damaging the egg?") and in the realm of science while the latter is a question of policy and feelings (how much do we want HIV resistance? What is the price we're willing to pay/risk we're willing to take? Does deliberately altering humanity open a can of worms best left unopened?).
Conflation between normative and positive meanings are quite common across a wide variety of domains and can cause substantial confusion as two people can think they're talking about the same thing but actually aren't.
Even in the "should" case there's a bunch of confusion as to what sort of things should count as "eugenics", with some people wanting the term to apply only to coercive measures and others wanting the term to apply to any deliberate changes to a population's gene pool (and theres the grey area in the middle where financial incentives happen).
Note: A lot of politically fraught words will have a number of similar but different meanings as various interest groups fight over them. From "war" and "violence" to "culture" and "science" to "person" and "rights".