Or because college costs are likely to increase over time (and faster than income for most parents of high school and college age kids).
On a related note, kids going to college just as a typical* recession hits may find the double financial hit of parental income loss, while states defund their universities to balance budgets, resulting in higher state university tuition and worse state university financial aid. Historical tuition levels indicate that state university tuition tends to be stable most of the time, but spikes during typical recessions.
*The COVID-19 related recession was atypical in that wealthy people who owned capital did quite well (see the stock market), so that state income tax receipts were often better than expected.