Frat Externalities

This 2002 editorial in the Cav Daily argues the University is right to subsidize fraternities (in the form of loans). The argument is essentially that fraternities bring so much good to the University community, that the University really ought to do everything possible to maintain an extensive greek system. Here's an excerpt:

The fraternity system’s contributions to the University community reach far beyond the undergraduate level. The fraternity experience trains men for success, making an impact that continues to be felt as an alumnus. With the Greek system at heart and the University as a backdrop, fraternity alumni continue to be integral supporters of the school through time, energy and financial donations.

Without using the economic terms, the author is arguing that fraternities produce positive externalities for both the University and the community, even though their primary output is apparently training "men for success." Hmmmmm. Are these the only externalities from fraternities? And what IS the primary output of fraternities?