But that's part of the math - cap capacity at MK and spread the crowds out to the other parks.
Or more specifically, cap demand for a specific lower end tier of admission. Not really all that different from having block out dates for Annual Passes and CM Main Gate passes. The problem back then tho, was it was an all-or-nothing block on admissions. Now with reservations they can say specifically "I'm ok letting in 10k Annual Passes and 3k Main Gate Admissions" rather than the all-or-nothing approach from before.