AGNES ,there are several things that you can not ask why .
On the beach,thanks for understanding us ,most things you said were true ,after Olympic Games ,the flowment still increasing ,but the capacity of route have not been enhanced ,that is why we have the flowment control.Furthermore ,if the weather en-route is not good , we normally give that restriction to reduce stress of controller ,I found another post here to complain the delay in Beijing ,I think the reason is most because of bad weather rencently .