You wouldn't be able to do October 1 anyway, because the park would be at capacity. Just like often a person couldn't get into MK or DL on New Years Eve or right around Christmas because it would be full already. About the only thing it changes is the incentive to start camping out like 12 hours before the gates open, which would be the situation if there were no park reservations. If there weren't reservations, it would be a first-come, first-served system so people would be outside as early as humanly possible on the morning of the 1st - or even the evening of the 30th - to be sure they got in. Personally I would much rather plan things in advance and know whether I can get in on a particular day than have to park my buns on a point in the sidewalk overnight like I'm getting concert tickets (ok, I was a nerd, so it was Supreme Court argument viewing, but that's not the point!) - I'm not 19 anymore!