Sometimes Universal makes shows or attractions based on less popular IPs because they have a cool idea for a show and look for something that fits that mold.
Backdraft and Twister weren't mega movie franchises. But they made for cool effects shows.
Waterworld is brought up a lot. But plans for a Miami Vice stunt show were going around before that. (With some elements ending up in the Epic Stunt Show Spectacular when USF opened.)
No one remembered the Earthquake movie that ride was based on, but they liked the concept of experiencing an earthquake, so why not?
One of the earliest attractions at USF was based on Murder She Wrote. Then later replaced with Xena/Hercules. Which were like the cheesiest of TV even when they were popular.
Some things can be fun without a well performing IP. The sign could say "Spy Thriller Stunt Show" and people would love it. I know I loved the "Wild Wild Wild West Stunt Show" back in the day.
Heck, it's a theme park. People will wander over and just get in line for anything that's there. How else would've Fear Factor Live been open for so long?