I'm sure someone from Tech Services can chip in here, but Action Theatre was a pretty high cost attraction.
The seats have a lot of hydraulic moving parts and they would break down fairly often.
Also, when I was there in 2004, the projector was still film. Occasionally the film would break or burn out and they had to splice the film back together.
The main reason it still stands is probably the workshop for Tech Services underneath, which basically handles all of the speaker and microphones in the park.