Perhaps this is what happens when you let successful directors go crazy and have full control over writing the story. Some directors just aren’t top-tier at writing like professional writers turned directors (e.g. Christopher Nolan). In Prometheus, the characters don’t behave logically and there are some gaping plot holes. I had to read this webpage (warning: spoilers) to figure out what the heck the director was trying to say. It’s still bad writing.
On the good side, there are some (unintentionally?) funny moments where you watch the characters do dumb things and get themselves killed. Kind of like in a horror movie, except the visible minorities don’t die first.
The movie is like a scifi horror flick. It’s alright. It’s not awful, but no masterpiece either.