“People wouldn’t go to a mixed college because of the stigma involved. “
There is only a stigma in the minds of some people because THEY stigmatize it. I have no problem with mixed colleges. Two of my children met their wonderful zivugim there, and I could not be happier. There was a time when there were no Touro Colleges with separate schedules, and all the frum kids went to Brooklyn or Queens College (otherwise to a branch of YU). They are the parents of the generation that now does NOT go to mixed college. Should anyone have a chashash on those parents? They seemed to turn out well religiously.