however, the funny thing is, when eventually a film maker comes along and makes a film that is both new, unique, and outlandishly successful, then suddenly its "obvious" and Hollywood starts to copy that, but it takes forever for the right person to be in the right place for that to get moved forward, so you end up with rinse wash repeat stuff for the longest time.

For example, HBO taking a risk on Game Of Thrones or the initial conception of the new Marvel movies (I'm talking about Iron Man, the first one from 2007, and so on, when it was still novel), Breaking Bad was novel when it came out too. Same with The Walking Dead (the plot elements, not so much the idea of a zombie horror)

Its so weird how this industry appears to work from the outside

I think one of the reasons Hollywood avoids many video game franchises that people would sort of expect them to adapt or sequel is a lingering hangover from the FMV craze of the 90s. Hollywood Producers worked hand in hand with a bunch of videogame companies, lost a ton of money in the process, and seemed to come out of that distrustful of two-way working relationships with videogame companies.

That reason seems directly relevant to GK in particular: GK2 was quite successful in Sierra terms, but still somewhat unsuccessful in Hollywood (accounting) terms and likely still on some Hollywood producer's books as an old loss.