There's science reporting for you.
I would like to take a moment to make a plug for SWE. The whole question of "why are women a minority in engineering" has been asked before. It's a complicated question. There isn't a simple answer.
But every year, the Society of Women Engineers (SWE) examines the dozens of notable studies around the question and publishes a literature review - the review of 2013 was completed and added in the spring of 2014. It's big reading. It's complicated. But if you want to figure out the puzzle of women in engineering, that's where I think you should start.
This year the first few pages make you think SWE is just tired of reviewing the same ideas by new authors who've never read anyone else's studies... they make a plea for academics to study fields outside academia, stress the need to ask questions around the intersectionality of race and gender, and mention (yes) lack of controls in many studies. But they find some good stuff that was published too... feminist critiques of engineering, programs for girls, engineer identity trends. And they find that just like in other fields, women leave engineering because they don't like their boss, don't find meaning in their work, or just have other interests. Are there things engineering could do to be more accommodating? Sure. But articles like the NPR report, that are all about how engineering is hostile, are not very well founded.
And they run the risk of scaring away some women who'd be great engineers because they don't aren't featuring any successes... if a woman likes her job in STEM, that's too boring to make a headline.
People have a tendency to criticize movements for being unorganized, even if they've never tried to be part of the organization. Don't do this to SWE, I'm telling you. My membership may be 12 years so yeah, I'm biased, but the work they do is important and the research is fascinating. Don't oversimplify this, and don't skip over the work others have done.