I follow a channel on Youtube that is run by I guess we’ll say an adult performer. In one of the videos he was describing the year he spent working for Disney as hell on earth. I’m sure there will be plenty of regional guys applying to the newest C-scale operation.

^^^ This...

Could even be Huey, Dewey, and Louie at the controls! They are Donald Duck’s nephews.

They'd have to move it. The monorail near the Magic Kingdom transportation building blocks the approach & departure at one end, they'd have to significantly lengthen it too.
Probably better to relocate it to the extreme north end of the property and plunk it down there instead. Restrict it to Disney flights and those wanting to pay Disney rates to use it.

The concept is not new. The original AirTran (not the ValueJet version), was exactly that, but instead of flying into major hubs we flew to secondary airports such as ALB, PVD, RIC, etc.
It was proving to be successful until SWA moved into MCO and started flying to the very same cities with multiple flights per day, and charging lower prices.

I had this same thought at one time.

Ended up being the best cruise I've ever taken and the experience wasn't anything like I had expected - to include your thought of 3000 kids running wildly about, primary colors at every turn and not being able to turn around without bumping into some character.

They do an EXCELLENT job of keeping certain areas of the ship 'adult' only - and they mean it. I watched a few crew members get a couple of 15-16 y/os out of the adult pool area. There was no turning a blind eye to it.

A cruise with thousands of kids trapped on a boat?

All E-Ticket rides there.