Designing it to handle those crowds would require Lego to fundamentally alter its concept of individual play-driven attractions (as opposed to attractions designed for large and more passive audiences, such as those on a roller coaster or watching in a theater).
So that leaves a couple other options for reducing crowds: Jack up the price (the Discovery Cove model), or put the park in an out-of-the-way place. Lego's decided, I suppose, that it better serves its family audience with the second.
That said, Lego's not picking bad locations for its parks. Carlsbad is beautiful and has lovely family-friendly amenities near. And this Kansas City suburb appears to have the yuppie demo that Lego's after. And it's located reasonably near a major interstate, as well.
So I think they'll get their million a year there. Yes, Legoland could do five million a year in Garden Grove or six in Orlando. Legoland reminds me of an art-house filmmaker, who could try to make a blockbuster, but is actually happier making a living crafting critically acclaimed films that relatively few people ever see.
The metro area is already a tourist destination. The second KC metro Bass Pro Shop is being built less than 30 minutes away, which draws in tons of families. A new arena is being built downtown. The speedway was built in KCK.
The city is becoming a theme park destination city
Oceans of Fun (Cedar Falls property) is in KCMOSchlitterbahn Vacation Village is being opened in KCK