The problem isn't lack of interest, the problem is that Disney's been making bad movies for the past 10 years.
I'm not certain about your doubt in the lack of interest part' Indiana Jones was a novel concept in 1981--a period where Lucas could repackage a form of storytelling not seen in 40 to 50 years, so it seemed fresh, and had the most serious kind of story for a character of that kind. The problem is that the novel concept was successful, but competing with a moviegoing culture who--by the 1980s--were obsessed with sci-fi and loud, violent action movies, and if one adds in the appeal of action set in times which resemble your own, it was quite attractive. That cannot be said of adventure films forever stuck in the 1930s (I'm referring to the OT Indiana Jones).
Those who record the history of film lazily sing the praises of the IJ films as successes for Lucas and Spielberg, but if one looks closely, they would see a pattern where, despite the reputation of
Raiders and its creative team, the sequels were not the overwhelming success of
Raiders--in fact, 1984's
Indiana Jones and the Temple of Doom ranked 2nd in the global box office behind
Ghostbusters, while 1989's
Indiana Jones and the Last Crusade (aka "one of the good ones") was outperformed by
Batman. Some will argue that the appeal or fresh nature of the high earners has something to do with their beating Lucas / Spielberg movies, but again, I believe the culture--the moviegoing culture did not find the sun-baked, dusty,
old world of Indiana Jones as appealing as two high-fantasy films set in then-current times.
This perception likely carried over into IJ's not too stellar ancillary market performances as well. For a George Lucas-related example, Kenner's
Star Wars line of 3 3/4 inch action figures / playsets ranked as one of the biggest toy successes of the 20th century, yet the manufacturer's
The Adventures of Indiana Jones line of similarly scaled action figures / playsets was an underperforming flop, despite the heavy marketing campaign for the line based on
Raiders's theatrical success.
Then, there was Marvel's
Star Wars comic book, which ran for 107 monthly & 3 annuals issues from 1977 to 1986. While the SW comic ran out of creative gas not long after 1983's
Return of the Jedi marked the then-advertised "end" of the SW saga, it had a healthy run for a movie adaptation. The same could not be said about Marvel's
The Further Adventures of Indiana Jones monthly comic, running for only
34 issues from 1983 to
1986, with its final two years on a bi-monthly published schedule. Again, there was an established pattern regarding the
perception of Indiana Jones as an appealing property, where the once-in-a-generation creative might of Lucas and Spielberg was not enough to win the pop-cultural Gold Medal where IJ was concerned. Whether in film, comic books or toys, IJ never had the wide, demographic crossing power of a
Star Wars, or new film concepts breaking through in the 1980s, arguably
speaking to core interests in a more effective manner than IJ.
The post OT-IJ films fared no better, had more appealing competition, and were viewed as largely disappointing with a side order of "why was this produced?" Every film concept--no matter how popular (or
believed to be popular) runs its course. Indiana Jones finished his in the 1980s, and even at his pop-cultural height,
most of his filmed and merchandised product was not the runaway game-changer, nor did it leave moviegoers actively calling for more.
Speaking for myself, I never actually finished it and I was so looking forward to it.
