This informative chart from the usually funny PHD Comics offers a compelling explanation as to why the cost of higher education is rising so quickly:

I think it leaves two things out: first, since the 1980s, states have been trying to get out of the higher education “business,” which is why most universities– EMU included– are only a third “public.” Second, it isn’t just university presidents who have rising salaries; rather, I think it’s as much about all administrators having rising salaries and also rising numbers– that is, there are a lot more administrators around nowadays than there used to be.

How do you reconcile the chart showing “average state spending on higher education” generally matching inflation from c. 1965 to 2000 and exceeding inflation from 2000 to present, with your statement that “since the 1980s, states have been trying to get out of the higher education “business””? Those seem directly contradictory.
Someone who knows better than me can attempt to explain this and I of course may very well be wrong. But if you look at about 1980 or so, you’ll notice that all the lines are about balanced. In the mid to late 1980s, they start to diverge quite a bit, and while state funding in terms of average dollars increases, the costs of tuition and fees (not to mention presidential salaries) increases much MUCH faster; therefore, state funding, as a percentage, is way down.
I’m not entirely sure that is the right explanation though, and I guess I’d want to explore that average state spending line a bit more, especially in the 2000s.
I guess it seems to me that all that just supports the arguement being made, which is that state funding has generally kept up with inflation, but university presidents’ salaries (and probably salaries of other top administrators) have significantly outpaced inflation, and it has fallen to students (through hefty tuition increases) to pick up these increased costs.
While not so true currently, energy costs were a big deal several years ago. Also health care. For several years, the increase in health care premiums were double digit increases With labor as the largest expense, and health care costs increasing dramatically, it’s not out of the question that higher ed costs outpaced inflation.