> This is also why there couldn’t be a good third movie, there’s nowhere natural to go after action.

I felt the third Alien film actually made a pretty good punt at this; it's not a perfect film without its issues, but I rather like it. The "female lands on abandoned prison planet with a bunch of violent criminals" setting was a good direction to go in after the first two films. It would have been better if they had focused more on the prisoners and such and less on the xenomorph running after Ripley (especially in the second half). In spite of the problems, I still like it more than Cameron's Aliens (which was certainly not a bad film, but also suffered from some issues IMO).

A problem with "big franchises" type of movies is that studio people with seemingly no sense of what makes movie great get involved and make things hard for people who want to do anything different that could make a sequel work. "People paid for aliens chasing Ripley in the previously films, so we must have more of that!" I have no problems they're focused on their investment and money, but it never seizes to amaze me how poorly these people sometimes seem to understand their market.