I doubt STEM companies are abnormally altruistic in this sense. If they could get away with it, they would. Unfortunately for STEM, hiring low quality engineers is much higher risk than hiring low quality marketing interns.
Whether or not it is the intent (difficult to prove, to say the least) it is the effect.
- Afterschool classes and clubs require parents who are free after 3.30pm to drive you there and back.
- That spring break trip to Rwanda to help underprivileged youths would look great on your college application! Too bad it costs $500 to join the mission.
- You're not taking 4 AP classes and volunteering on weekends? You must be lazy, and its certainly not that you have to work 20 hours/wk after school to help put food on the table.
- etc. etc.
(I say this as a very privileged person who was fortunate enough to have two full-time parents -- but also as someone who knew people who weren't.)
It's rigged, but only in the short term.
She has a dual major in business and arts, and wants to work on Broadway doing marketing or production work. I find it sickening, and it saddens me the way interns are considered a completely free, fungible, and exploitable resource just so they can get phony career advancement "at some point."
My significant other will be graduating college soon in exactly that predicament, she wants to work on Broadway.