This isn't a question of an adultolescent wail of "do it for me! I'm entitled! I wanna go!" Instead, it's a statement that the cost of university education should have some tenable relationship to the earning power generated by such a degree.
I agree, so if one can't use the degree of their pursuit to pay for that degree, then it's an unwise decision and one should pursue a different degree. While we'd all love to pursue what tickles our fancy, unfortunately, not everyone's fancy is strongly marketable and decisions have ramifications.
Let's also not artificially segregate the notion of "tuition aid recipient" and "taxpayer". The two are the same individual, at different points in the individual's tax paying life cycle.
Except that everyone pays taxes, not everyone goes to college and only roughly 33% of HS graduates also graduate from college. So no, they most frequently aren't the same individual.
Perhaps it would help for you to think of your own children's public (presumptive?) K-12 education as being a time of you making net withdrawals on the education portion of your tax remittances. Were you unfairly requiring other taxpayers to subsidize your family's personal decisions?
Once again, not everyone goes to college, and only about 33% of HS graduates also graduate from college, the mass majority of people DO go to public schools K-12, you're comparing apples and oranges.
An important difference is that K-12 are children. Colleges students, though there are a few exceptions, are over 18 and adults. As a child you're the responsibility of your parents / guardian, as adults one becomes their own responsibility.
Likewise, if you need to call the police to your home to intervene for a burglary, and you engage in public prosecution of the criminal, you are withdrawing--on average--from local policing budgets. However, both services are acknowledged to be valuable to both the individual and society, which is why they're funded. What makes these individual transfers fiscally sustainable is that they operate on a pooled insurance basis. No one individual is constantly withdrawing these services ad infinitum.
The police are a local, county, and state service, I'm referring to the federal government in relationship to college. Additionally, protecting a citizen's rights is what government, according to the Declaration of Independence, is instituted for, the same cannot be stated from public education.