Well its never a national rule so its always localized to the specific chapter when one becomes a scandal. But also Greek life is heavily institutionalized within most college systems and there are powerful alumni. Every school have a long reputation of trying to make sex scandals go away as quickly and quietly as possible.

But also that requirement is usually presented as a challenge to the prospect to accomplish on their own. To prove you're the right type of hot to be in our clique etc. Many young women will volunteer for this.