I'd say based of Camp Jurassic/Dig Site at DAK's popularity, kids still love interactive physical environments. Problem is that TSI is a severely outdated concept that hasn't been freshened up since it first opened. Camp Jurassic has a lot of interactive touchpoints (water geysers, slides, dino feet, etc.) while TSI really only has 3 caves to explore and an outdated Fort.
A fully built out TSI with actual interactive and interesting experiences would draw more people into it.
Not defending TSI, I think it's past it's prime, but I'd imagine it'd be more popular if it was at Camp Jurassic's caliber. My biggest gripe with this project is the removal of the waterfront and the steamboat, such a significant part of the MK aesthetic/experience. I don't mind if they permanently dock it, it's such a nice view at night.