Why do college students join the GREEK life?

I will enroll at a university for Fall 2015 and I will know much more about the Greek life, though I’m not interested; you never know. But why do people join it? I don’t know much about it, but I heard that costs and fees are involved and requires some hours.

Isn’t this a waste of time? What if a student is taking out federal loans and yet he or she is in an expensive Greek organization.