Because the OP asked.
It's one thing if you know for sure that the fraternity really IS going to bid the guy. But there are times where a group just wants to keep a rushee from looking at another group...they just want to keep the rushee in question on the string in case one of their other guys doesn't sign. Too often the guy gets tossed to the side when the guys they REALLY wanted sign on.
As for dumb younguns - male and female - you need to educate them before they start opening their mouths.