I think I can give perspective as a woman in STEM. We aren’t encouraged to be interested in it. From a young age we’re advertised toys like baby dolls, Barbies, bright pink Lego beauty salons, kids makeup, pretend kitchens etc. The boys sections always have pretend DIY benches, action men, hot wheels, nerf guns, cool Lego sets, fun science kits. We are taught in these ways to grow up looking after babies, to look pretty, to be a homemaker or a beautician. While boys get taught they can have any career they want.
Many of us are programmed from that age to be what society expects of us, and it’s improving with parents starting to care less about pink and blue toys, but slowly. I will also add that boys equally have that pressure to work in more physical jobs, that it’s not masculine to be a homemaker or beautician.
Then, those of us who do get into typically “masculine” careers often struggle. A lot of the guys at my workplace don’t just see me as a mechanic like any of them, they see me as a female mechanic. Think how strange it would sound for me to start calling them “male mechanics” as if it were abnormal. It’s treated like this particularly impressive thing when I’m just doing exactly the same as them. And some of us will face sexism and/or sexual harassment to the point of quitting.
TL;DR We are “not interested” because we’ve been told all our lives that we shouldn’t be.