There's a guy on the DIS, who in their FP+ discussions, tried to pull together all the THRC/OHRC's property wide. I googled and did see it in one discussion here, but probably people aren't too familiar with it.
http://crooksinwdw.wordpress.com/2013/12/14/theoreticaloperational-hourly-ride-capacity-at-wdw/ For the Studios, TSMM is listed at only 900/hr OHRC. I found an old post from here, where someone said it was 1/3rd the capacity of Kilimanjaro Safaris. If that's at all in the ballpark, that's really low for a headliner attraction. Star Tours and RnRC were listed at 1600, ToT at 1800 and Great Movie Ride over 2100. It doesn't have to be an "either or" proposition, WDW could have screwed up by not having enough attractions in the Studios AND built something with poor capacity. Personally, I always thought WDW got scared of "overbuilding" rides like the old school Epcot attractions, but then they swung the pendulum too far the other way. They guaranteed the ride would always have a line, therefore it was "popular." The anti-Hogwarts Express issue.