I am not sure what the reason for it is, but I go to DL alot and sometimes mainstreet is open and some times its not. If it is, as posted before, there is a velvet rope at the end of mainstreet. I have been there times where I have had to wait outside the gates for DL to open and there have been sometimes where I have waited at the rope. Like I said, I don't know why. You should call Disney and ask.