The US is an empire and need their military. As retarded as it sound for normal people it's totally acceptable to use schools as recruitment center there. To put it bluntly, ROTC cadets are young people too dumb for west point but still aspiring to be more than cannon fodder. It's a program you do at the same time as you attend college to prepare you to be officer.it's a civilian school i don't think it's very routine there.
seriously just put your guns in a bag when carrying them trough civvies, who you shouldn't expect to know better.
So yeah, it's normal there to see wannabe officers in uniform carrying guns replica on a campus.