I have a degree in engineering from 20 years ago. Back then, there weren't many women in my science, math, and engineering classes.
Maybe women don't want to be engineers, scientists, etc.
I'm not going to recommend the career to my daughters, one of who is much smarter than I ever was. They are not good careers to have if you also want to be a mom.
One of my daughters is great at math, so I am encouraging her to be an accountant. She'll be able to work part-time when she is a mom.
I think my extremely gifted daughter will make a great teacher. I don't see her in the corporate world. She is not competitive. She also loves homemaking activities like sewing, cooking, etc. She's smarter than my son (who is also very smart), but she just has a different personality.
I don't know what they're talking about. Women tend to be attracted to the life sciences. If you look at the numbers of women in medical school or in doctoral programs in the biological sciences, or if you look at the citations in major journals, you'll see a lot of women. Women like studying living things; it's in our genes. Not many of us like rocks, physics, and math (though my cousin does physics at a major university).
Many women also don't do as well with spacial relationships than men do, so we are also less attracted to chemistry and physics.
I do think expectations have something to do with it. I know families in which there are very, very bright, talented girls who are sincerely interested in the sciences and would like to be physicians or researchers, but are actively discouraged by less-educated, unsupportive parents.