my assumption is that university administration is banking heavy on participation in the graduation ceremony being seen as a crucial rite of passage and formal family event (your grandparents came in from out of town for this! we want pictures, don't cause problems!).

which is probably a bit of a fool's gamble, but less than i would imagine considering the changing demographics of state schools. they seem to be shifting heavily away from children of working class families and towards children of families with high net worth who provided some level of support for higher education to the student, and therefore give the family elders a perceived "stake" in the pageantry. especially since a lot of those kids might well be moving right back in with their parents after the ceremony.

when i first went to a state school in the late 90s, my cohort were almost entirely bozos like me on scholarship that saved up during the summer to cover food/expenses and had some family kick in help to cover shitty but affordable campus housing. when i went back to finish a decade later, most of the students were from rich families who were paying for everything. there were exceptions who were working like dogs + scholarship to get through, or the occasional non-traditional military on the GI bill. but aside from them, most had never had some shit job in a fast food joint or landscaping. the tuition, housing, and meal plans were all exorbitant and of "top" quality, because the state university was now a place that was marketed to appeal to high net worth families.

i gotta imagine that changes the calculus for a lot of students at state schools.

also, going to graduation is a bit of a self selection thing. not going means saving like $80 on the single-use costume and not having to sit there for like 2 hours or whatever and deal with traffic. it does seem to trend towards people who have family who want to cheer for them. even before this latest genocide, administration would lay it on thick that if someone was disruptive they would interfere with the credential in some way. which i am sure is bullshit, but empty threats can work.