This really depends on the state. In Montana, for example, it is a legal requirement that parking is funded separate from the rest of the school. This means that no tuition can pay for new lots or enforcement. Fees gathered from normal parking rates and fines are used only to maintain and/or improve the parking.
This seems like a really convenient way for schools to pass the buck on to their students, while administrative bureaucrats continue to rake salaries in the hundreds of thousands of dollars per year.
How is is not? Many colleges now have more administration staff than education faculty... I know that at my university they constructed a massive new building to house their growing administrative staff.
Not quite 50/50 but the University of Oregon lists 2075 faculty and 1521 administrators and officers of administration. Also, 112 of those faculty are listed as retired.
Why should students get free parking? It is a choice to use the parking facilities (those with mobility issues aside). I am in favor of parking rates being based on commute distance. If you live within a reasonable walking distance, say two miles, then you can't get a parking pass. Then concentric rings out from there with decreasing cost. While there would be some address fraud, it would help to reduce the dependence on parking.
I went to a university that has no shortage of land to expand to. This meant that they have a couple of very large parking lots for on-campus students and some large commuter parking lots. If you didn't mind walking, parking was easy to come by. Those that complained about a 10 minute walk thought there was no parking. Funny thing was that it was easy to cross all of campus in less that 15 minutes. Really is a matter of perspective, I suppose.