Jothar posted: “Why should a co-ed college be any more acceptable than a co-ed high school?”
Because many single-gender high schools offer good education. However, for a really good education in many subjects, one can only find it in a mixed school. Not to mention graduate-level work.
And some Torah Jews (men and women) may be interested in education for its own sake–whether in science, medicine, Yiddish culture, Tanach, English literature, law, etc.