But the reason these coaches are able to get these salaries is because of policy decisions made by state governments. To some extent, voters have a civil duty to decide whether they agree with this policy, and vote accordingly.
It's true that someone has to write their checks, but the point is that that someone is the state government, which is funded by our tax dollars.
On the other hand, most state schools are getting less and less money from the state as American state governments turn away from funding education.