If the film rights had been included, Disney would have been significantly more interested, but having to play with Warner (and be required by contract to listen to JKR's final word on everything), didn't help matters much. Nobody on Disney's end thought it'd be this popular for this long either!I find it arrogant and stupid that they didn’t just agree.
As an elder Millennial (Xennial) there was 0 doubt that a well-realized HP environment would basically print money.
There is a universe where JKR shops film and theme park rights at the same time, maybe post CoS or PoA, and we see Disney go for the whole package. This was not it.