Well, The difference between me and possibly you are expectations. When I go to see a comedy - I expect to laugh. When I go see an action movie, I expect to see fights or shootings. When I want to see a thriller, I expect to be on the edge. Unfortunately, a lot of people when they want to see an action movie, they expect a script to win an Oscar, they expect the best actors money can buy and billions spend on budget, a great comedy script and all that. I don't call that all reasonable expectations.
Transformers was a sold movie for action. I got exactly what I wanted from it - firefight + some story to go along with it. The 3.1 points loss would go directly to story.
But yes, if you didn't like Prometheus, you will not like the Alien as it is just a continuation of it and many expected nonstop horror killings and it's not what it was designed to do. The movie is amazing,but requires some thinking and a lot of people for some reason don't want to do that...
ps. I didn't like the original Alien movies. I found them pointless, predictable and just stupid.