I have a suspicion that there's a cognitive bias at play here, whereby men unconsciously overrate the competence of attractive women and underrate the competence of unattractive women. While I have no evidence to back it up, it does a better job of passing the sniff test than the implicit assertion that men are consciously hiring unqualified women simply because they're attractive.
Only men?
I don't consider it likely but it seems mathematically possible that men are entirely even handed on the appearance of women but that women are highly partial to more attractive women. That would mean that as more women entered higher echelons of companies there would be more bias towards hiring attractive women [for top positions]. If the effect was greater amongst more attractive women - like stereotypical high school girl groups of Hollywood movies - then the effect would quickly magnify until only the most attractive women were allowed, by other women, to attain top positions.
I'm not at all saying this is the case but just questioning whether there's a basis in science for your apparently pinning the apparent bias on men [alone].
It also strikes me that perhaps the person writing the story is attracted to power. That would make those women appear more attractive than they otherwise might. A further possibility is that after attaining positions with good wages they then were able to acquire the ability to stay (or become) more attractive - basically flipping the cause and effect.