The sources and psychological research on this question are endless. Not to mention all of our personal experience, which is entirely consistent. The problem is actually twofold.
Part one: the comfort of mediocrity
Yes, many (not "some," "many") men don't appreciate intelligent, self-confident women.
It's easier to win over an insecure woman who laughs at practically every joke just to be accepted, who looks at you with doe eyes because she feels honored you're spending time with her. You feel much more confident. So everything becomes simpler. It's easy to play superhero when someone always goes along with it.
An insecure and perhaps not too bright woman is easier to manage. More predictable, she settles for basic conversations and hobbies, doesn't force you to improve, doesn't require you to be interesting. One could argue such a specimen also makes your life more boring and predictable. But many men, simply, are banal and perfectly fine in a banal existence.
Their dream really is a 1950s American lifestyle with a devoted homemaker, barbecue, the game, beer, home ownership, steady job. I've met tons of them.
A beautiful, confident, and intelligent woman is seen as unreachable by many men. The idea that many women lack self-esteem is correct, but it's not a monopoly. The problem is primarily male, especially in a society where culturally the male gender always makes the first move and bears the risk of failure.
Part two: smart women attracted to the worst
Many highly intelligent "high performer" women prefer to date and give chances to the worst ones. Whether outright "losers," womanizers, or people with no goals or dignity. Mathematically, this pushes others away who feel sidelined.
If you're a very intelligent, tough woman, you'll likely pour enormous attention into your work, career, passions. You simply need to achieve. It's in your deepest instinct. This makes you invest less in relationships because you put less "brain" into them. Where you don't invest, you don't get returns.
Many "toxic" men with pathological egocentrism, narcissism, and Machiavellianism simply have such infinite self-esteem that they aim straight for these women. Taking "priority" in the pecking order. In a sense, they "feed" on their partners' strength. They compensate for their deep infantile needs. In return, the women get what is effectively a "fake" alpha male — compatible with quick hits of easy satisfaction that carry long-term consequences.
In summary
For most men, it's simply more convenient to have a partner who's insecure and sometimes mediocre. Many particularly confident and smart women are naturally attracted to toxic relationships because they seem to offer more for less investment.
A lovely mix. Note: there's always the risk of "self-reporting" bias in these studies, but I believe the foundations are solid. And no, we're not talking about everyone.
