While Greek life does exist at Columbia, most students would agree that its presence is not particularly notable. Most students know of only a handful of fraternities, and sororities are almost never heard from. For many students, fraternities are just houses with parties that serve as a last-minute social activity if no other plans are available. Most students at Columbia value individuality and diversity of experience too much to stick to frat parties every weekend.
The Greek system at Columbia is very self-contained. Most members only really interact with each other, and the majority of students has little to no interest in Greek ongoings (apart from the occasional scandal, which affects Columbia's public image—Google "Operation Ivy League" for more details). Lots of Greek members are athletes, another group in which most students do not include themselves, which could contribute to the overall lack of interest in Greek life.