They took a look at what DC and Marvel were doing with building cinematic universes with varying levels of critical success and near guaranteed profit stream year-over-year and thought “We could do that! What do we have in our roster? Monsters? People love monster movies!” and kludged something together to spark it off.
Except they forgot to build a story underneath that people would want to see more of. They got wrapped up in world building, similar to the current?? trend of pop fantasy books.
EDIT: And it’s only now I realize this wasn’t current. D: