True, but how about midnight or 1:00 a.m.? I just checked the schedule and even now, at the peak of summer vacation season, the MK closes at 10:00 p.m. most nights, with Epcot and DHS at 9:00 and AK at 7:00.
Disneyland is open every night until midnight! And DCA until 10:00.
If I were planning a trip to Florida at this time of the year (in violation of my policy of not going east of the Rockies between May and September), I'd sure like the idea of hitting some parks in the morning, staying in a pool or air conditioned hotels and restaurants until after sunset, and then coming back for a few more hours at the parks. Maybe it isn't feasible due to shift-length requirements, but somehow the Disney folks in California manage to do it, and I'm going to bet that working-hour regulations are stronger there.
Disney could even offer an evening discounted ticket like they used to do at Epcot*, although that would only appeal to people who don't want to go to the parks during the day.
* Was that only during the Food & Wine Festival?