As others have mentioned, many of us do what we can with what time we reliably have available. You more than double the length of an event if you allow the entire queue in. (Everyone who makes it in going twice + more time for clones to join queue + more people who couldn't have been on at the start) It's impractical to do the entire queue for a good amount of events for these reasons. We don't open multiple events for similar reasons, as it's difficult to schedule multiple host being reliable available for huge swaths of time. Sometimes it happens that we can do things like this Especially with ride-a-thons where the entire event can be handled by one host, but we feel we do a good job taking care of our population, and in many way, such as queue prizes, go well above any beyond the original VMK in addressing such issues.
The events however begin at a specified time, and it is your responsibility to be there on time. Consider it as an appointment. We'll do our best to make sure anyone in the first few minutes gets in. Please keep in mind you're responsible for determining if you think you'll get in by the time the event ends.