The desire for power and control is negative, destructive, and pretty much sums up what is wrong with humanity.
Which for
Darklords is fine, because they're supposed to be villains.
And an appallingly sexist stereotype when applied to men.
So why not give it to the female Darklords?
It's appallingly sexist to make them all have the stereotype of "must have a man and/or baby," so why not give them a different stereotype? After all, they're arch villains; it's OK for them to be cliché, so have them be
different types of cliché.
Calling it "romance" is to belittle it. The desire to have a family is constructive, and essential to the survival of the human race, just as the desire for power and control is inimical to the survival of the human race.
And we're not talking about constructive desires. We're talking about how female Darklords are limited to "is evil because she can't have a man" or "hates all men, therefore is evil."
A male Darklord whose
only motivation is "evil because he can't get a woman" would be incredibly boring, which is why they gave Dominic--who was evil long before he was old enough to realize that girls were all nice and pretty and stuff--a country that he actively manipulates, an archfoe with the same shtick he's trying to outmaneuver, and a political day job he actually performs
in addition to falling in love easily.
A male Darklord whose
only motivation is "hates all women, therefore is evil," would be incredibly boring and probably would be written out of canon quickly. In fact, Duke Gundar, who was basically an evil vampire whose entire shtick was that he forced people to pay an exorbitant tax every time a baby girl was born,
was killed off in the Grand Conjunction. (Ish; he became a skeleton, regrew his flesh, and apparently now wanders the land as a bestial, amnesiac vampire.)
It should be noted that, canonically, now that Gabrielle has Matton in her life, "she is less jealous of the happiness of others and no longer takes as much pleasure in toying with innocent folk." Once she got a man, she stopped being so awful. See what I mean?
If it is to become less sexist, Ravenloft needs to stop trying to be 19th Century Gothic.
What it needs to become less sexist is to give the female Darklords another motivation beyond one revolving around men or babies.
There are lots of domains that are pure fantasy, not based on any 19th-century novel: Keening, Vechor, G'Henna, Sithicus, Staunton Bluffs. And more if you allow for domains that are based around real-life events but not Gothic tropes: Falkonia, Tepest, Nidala, Souragne, Borca. You may or may not like them as domains, but it's proof that they were never limited to old novels.
Or perhaps it would have been better just to let the setting die.
What's sad is that you would have the entire setting die rather than just give a little bit of thought as to how female Darklords could be a bit more interesting.