It is my understanding, and I could be wrong, that when only public schools/universities were taxpayer funded, some segments of the population raised the issue of affordability (lack of access) at private institutions... leading to taxpayer funding for various private institutions.
That would be new information to me (so if you have a link, I'd appreciate it) but it's also probably harkens back to a time when a high school education was sufficient to enter more industries at an entry level. And the cost of college, public or private, was much more in line with the ability of students to self-fund a decent portion thereof.
A strong argument for reducing the cost of public universities is precisely that the current public high school education curriculum does not prepare the average American high school student to actually enter most industries. So, a responsible society has 2 choices.
1) Overhaul pre-college public education such that the students are employable upon graduation; or
2) Subsidize the cost of public university education to accomplish the same goal.
Failing to do either means that we're wasting the money spent on public, pre-college, education since it's largely insufficient for the needs of those it's "educating".
Since public school education prior to college is largely funded by state and municipality level funding decisions, this means thousands of independent entities (13,506) being asked to suddenly align education goals. You have a better chance of accomplishing the goal at the college level and if you can do it simply by re-allocating existing spending instead of creating new spending, it's the better financial option as well.
