At my school GDIs were just non-Greek, no negative connotation.
However, my mother has a yearbook from her college years that had a GDI editorial staff. The editors made all the GLOs have specific pictures taken or they couldn't be in the book. The had 3 sororities. One group was in pajamas w/sleeping bags/pillows etc b/c their rep was that they slept around, another was dressed like little girls (complete w/bottles, pacifiers and thumb sucking) b/c they were "daddy's girls" and the third had their picture taken at the town dump - b/c, well, you can figure it out. They did the same thing with the guys and their reps.
Of course, the "we're better than you Greeks" GDI editors had their own picture taken and they had greek letters and talked about themselves like they were in a GLO anyway!
