I suppose in the end that is the point. It's the piece of paper that has the value/door opening ability, not the actual knowledge imparted.
Part of the problem with that route is that a big part of university education is the signaling and brand value, and that's hard to replace via tutoring. Maybe that won't always be such a big factor, though.
The mandate is that the UC system is required to offer spots for the top 12.5% of the current year's in-state graduating high school seniors, so this mandate obviously expands if university-age population increases. Which to be fair is sensible: it makes sense for the state university system's size to be roughly proportional to the size of the state's university-aged population. But then you should fund it proportionally too.
Here are some numbers I put together a few years ago (not updated since 2012): http://www.kmjn.org/misc/uc_funding.txt
Which is not to say overpaid administrators aren't also sucking out more money than they should be. The UC Office of the President (UCOP) is currently being deservedly raked over the coals by the state auditor, and I would not shed a tear if UCOP's budget specifically were cut. But in terms of big-picture trends, the state's per-student funding declining from $30k/student in the '70s and '80s to less than half of that in 2012 is a pretty good first-order explanation.
You'd think they would consolidate administrative services like payroll under UCOP, but UCOP doesn't even do their own (they outsource it to UCLA).
This is a problem caused by government, not a lack of funding.
But the decreased funding for research on the backend, and decreased direct funding for public schools, have made it so that schools need to seek out funding in other ways.
For example, they actively recruit full-fare foreign students now for the tuition. It has also caused tuition to rise, relegating the ability for students to pay their own way via a part time job or two to the past.
EDIT: And yeah, the increased demand for a fixed supply increasing the price is what I meant by "they're not minting new Ivys". I wouldn't agree that it's a bad thing that we're educating more people to a high level, though.
Except that the top marginal tax rates also used to be much, much higher, so it was subsidized by the rich.
But then, there are also many more people going to college now, and there aren't any new Ivy League schools being minted.
If it gets bad enough, the pressure to find alternative ways to educate will build up until we find a good alternative route.