“At least in California, where I live, and Alaska, where I went to undergrad, tuition increases in public universities are coming about because of increased numbers of administrators, expensive capital projects on campus, and decreased funding from the state.”
You have the cause and effect out of order.
Increased demand enables price increases. Price increases enable more spending.
Now that demand is softening, net prices increases are no longer possible (at most schools). So spending can’t continue to increase.