You’re engaging in the same kind of bad math. You’ve created a scenario that demonstrates something completely different from what you are taking issue with. What you’ve described is an attraction that does not have enough capacity. You said peak design day hour was a bad basis of design, but nothing you wrote addresses how a 2,000 pph capacity is derived from a 3,000 people peak hour. You did it backwards, you picked a capacity and then made up demand models that it can’t handle instead of deriving your capacity from the demand model.
Knowing the shape of the day and your total demand informs the difference between your peak design hour and your capacity. This is where attractions per guest per hour comes into play, it is how you determine if 2,000 pph is desirable for a 3,000 people peak hour.