I believe it has something to do with ride maintenance. Like it takes 2 hours to shut down and 2 hours to start up. So if it closed at 2 AM, they'd be off at 4AM. But then early entry starts at 8, so they have to start up at 6 AM. Which means the ride would be on 22 hours of the day. Even something as simple as "oh, then close it at 11:30-1" is still adding a lot of additional wear and tear. It's their key attraction, breaking down because of HHN would not be ideal. Especially when the last few years, they've closed Mummy and JP for usual construction/refurb, and now even more importantly since JP will be closing for quite some time.