Ban Greek groups and you will get the same thing with different names - study club, eating club, literary society, prayer group. The name is different but the function is the same. With NPC sororities, at least there is (or should be) some adult supervision, standards of conduct, academic standards, and consequences if the chapter does not live up to that. Fraternities, not so much. Local Greek groups, definitely not so much.
Kids - er, young men and women will still get together to party, and some will still behave badly.