Yup. The Alien connections don't even have to be considered since the movie failed at all the basics of even working on its own.I've never been big into the Alien franchise. Seen the movies, got some of the bigger nods in the films (were probably a lot of smaller nods I missed). I still didn't care for it, all my problems with it were with this movie my itself, and nothing to do with how it connects to the Alien films.
I don't see how having terribly constructed stories is a step in the right direction for SF films. Having Ridley Scott, sure, but everything else? Fuck that.
It had ambition at least. It completely failed at it, but if the relative success of Prometheus can get some other, hopefully better realized, adult sci-fi movies made, then great.