Wow --- I was not in a fraternity, but to say they are a really, really awful idea...uh, why? Can you support that argument (with something other than they ignore me/exclude people)?
I had friends in them - partied with them, etc. I also lived in a dorm where, even though there was no Greek letters defining a group, people of like mind got together and did activities to the exclusion of others...so what's the difference? I then moved off campus for a few years where we partied exclusively with a group of guys up the street and our various close friends. Again...no greek letters, but the same impact.
So a group of people want to formalize what is, in fact, very normal social groupings. In fact, you can make the argument that fraternities, in fact, allow individuals to interact with a LARGER group of people than they normally would, and thus are in fact a social beneift, and everybody should be a part of them. They also do charity work, etc.
I have friends that still keep in contact with their fraternity buddies from 20 years ago...it's called networking, and it provides people with an upper hand in business for decades to come in some instances, just like alma maters, church affiliation or any other of a number of things influence business decision without merit.