It is about the origin of the term/field.

You are right that the field of genetics is of course applicable to humans, with a lot more muddiness when it comes to the ethics - not the point.

The term "eugenics" describes a certain philosophy/set of ethics which directly grew out of racist narratives at worst and some very loose interpretations of the scientific methods two hundred years ago at best. Furthermore it can argued that the "field" of eugenics never really attempted to shed this, even as of today. Thus, calling eugenics pseudo-scientific is considered fair game. At least that's my understanding.