Not Just a Ministry to Presbyterians

Appropriating a slogan from an ELCA colleague, "Presbyterian Campus Ministry: a Presbyterian ministry on campus, not just a ministry to Presbyterians." I really like that. I wish we could get that thought down to local congregations (and even up to denominational leaders). Too often discussions about campus ministry turn towards the number of Presbyterian students served. Usually this means PC(USA) students.
Most campus ministries of which I am acquainted have participants over the entire spectrum of belief. Many student leaders in PC(USA) campus ministries are not Presbyterian.
We should be celebrating this witness!
The Presbyterian presence in higher education has always been open to all. John Calvin wanted education for everyone, believer or not. While Roman Catholic institutions were founded primarily for Roman Catholics, Presbyterian Colleges were never just for Presbyterians. In the same way, Presbyterian campus ministries should never be just for Presbyterians.
So - congregations and leaders ask- "Why should we support ministry to students other denominations?"
Why not?
Aren't we to "Love God with all our minds?"