I never heard the term GDI until I came to GC. It wasn't used on my campus. Unaffiliated people were just that... unaffiliated people, or independents. And we were all unaffiliated at some point
UMgirl has a point. There are independents who can take or leave the greek system, along with independents who are interested in becoming part of the greek system but it hasn't happened yet. These folks should not have the GDI label applied to them unless they choose to apply it to themselves (possibly tongue-in-cheek). Then there are those independents who, for whatever reason, take every opportunity to bash the greek system... the type of people UMgirl is calling GDI's.
I have referred to my husband on a few occasions as a GDI. He is one of those people who can take or leave the greek system - it just wasn't for him. He doesn't mind the term, and, well, it *is* quicker to type GDI than independent... guess I'm just lazy
But he's definitely one of the "good" sort of independent.