Greek life is very big on the Mizzou campus, especially during football season and Homecoming. They hold events just about every month, and members are required to attend meetings every week. This can be very overwhelming for incoming freshmen. Frats are a little more relaxed with their rules, whereas sororities are very particular about everyone following the rules. The members usually live in the dorms the first semester and then move in to the house after they have been accepted into the frat/sorority.
Many people do not particularly like sororities and frats because the people in them act rude and sometimes won't associate with people who aren't in their frat/sorority or in a frat/sorority in general.