It's an extremely expensive ride - IIRC, the original cost Disney something in the ballpark of $80 million to develop. I'm sure each clone costs much less than that now that all the R&D is done, but it's still an investment that 1) the Studios haven't earned, and probably won't until Disney is ready to massively renovate them and b) would've been crazy to add to Hong Kong's budget when they were already developing Mystic Manor and Grizzly.