It's always interesting to me that people don't seem to accept California Adventure, and yet it has some of the best attractions on property, that everyone says they love:
Aladdin
Grizzly River Run
Soarin' Over California
California Screamin'
soon to include the Tower of Terror
Muppets
Who Wants to Be a Millionaire
It's Tough to Be a Bug
Golden Dreams
Regardless, I have many a time thought about why Cali Adventure does not do well, and the answer is simple--Disneyland profits off of locals. A vast majority of its visitors live in California, which is why they don't have much interest in a park about their home state, which hurts this park a lot.
Such a park would almost certainly do well in Florida, because the rides themselves are great, and given that a vast majority of Disney World's visitors are tourists, they would go to a park like this to learn about Florida--same reason I love California Adventure. Realize that the poor reviews you hear come from locals, but just about everyone I PERSONALLY know who has been (obviously from the East like me) have enjoyed this park. This is why Disneyland is trying to make their property more into a Resort, to appeal more tourists (which is working, by the way...they are solidly booking their hotels).