In you hypo, you have saved x amount for your children's education. Money that has been earmarked for college since, I presume, they were small children and you had no idea what they wanted to be. 18 years after they were born and 18 years of saving, your child comes to you and says that they think they want to major in something that you don't approve of or something that you believe will not render the proper ROR, so the response is to tell them to go pound sand and spend their college fund on yourself. Interesting...
Yeah, your hypo doesn't exactly fit us. When my wife first got pregnant, we were 22, I was unemployed, and she was an admin assistant. We were poor as dirt. We "compounded" that by my wife staying home with the kids instead of doing the daycare thing, meaning she was working jobs she could do nights and weekends instead of a real career. She's only been back full time about 6-7 years. It was hard as hell financially, and so we were late to start putting retirement money away. So no, I don't have the $600k to just turn over to them to go where they want and have a blast for four years, no strings attached. We're paying for this out of pocket now that we're doing pretty well and live frugally, and what we've been able to put away in the recent past. We've promised and committed to them to pay for them to get through undergrad at a good school, at no cost to them and without them taking loans, which comes with it's own set of strings attached as far as the schools where we can make that happen.
It's not about a return on our investment, at all. We're actually going to get out of this with less of an investment than many parents do. It's about one single thing...being poor SUCKS. We've lived it. You don't have to be mega-rich, but you have to set yourself up to make decent money and do a job that is in demand. If you have that, you can largely choose where you want to live, what kind of work environment you have, what kind of travel you do, what hobbies and passions you can pursue, and how to do good in the world etc. If you don't, you work where, and for who, and for how much you can.
If you aren't demand, everything is decided for you. You have to work where you can make $9.75/hr instead of $9 and hour, even if the boss keeps staring at your ass, or you're working on Christmas. It sucks in every imaginable way.
I don't expect a 16 year old to understand that. They think hey, if my art history degree doesn't work out, I'll be happy enough just selling shell necklaces on the water in my flip flops in Key West, or being a barista in Seattle. That's not the real world any more. There is virtually no pleasant lifestyle, no good schools, no nice safe neighborhoods, etc for the working poor/lower middle class. It's not like it was even as recently as when I was growing up. The world sucks for the working poor.
If my kid wants to skip college and become a nurse or a mechanic or an electrician, I'm cool with that too...no problem at all. Just so long as they have a profession that gives them options and opportunity.
It might be well different if we were mega-rich, and would always be able to subsidize their adult life or give them a couple hundred grand to buy their first house, etc. But that's just not in the cards...we're focused on getting them through school (if they choose) debt-free, and then making sure WE'VE got the resources put away to never bounce back as a responsibility on THEM. We do consider it a parental responsibility to prepare them to not be poor as an adult, just like we wouldn't want to send them into adulthood with Type 2 diabetes or a tatooed eyeball or two babies they had as unwed teenagers.