The nice thing about a huge school is that whatever you want to do, chances are you will be able to find somebody else who wants to do that too. If you want to party, you can find lots of people to party with. If you want to study, you can find lots of people to study with. If you want to hop on one foot across campus while singing the alma mater, you could probably find somebody to do that with you too.
Colleges like to talk about racial and ethnic diversity, but that's not the only type of diversity there is. There's also diversity of personalities. Colleges have that in spades - including the Greek system.