Was Prometheus the worst "sequel" ever? I can't say for sure, but it was horrible as science fiction. It made no sense and didn't even do its science well. Here's just one issue that renders the whole thing nonsense: They have excellent robot technology. Why send a passel of humans on this voyage, when the robots could have conducted the science without endangering lives?

I wrote a review about it when it was in the theaters:

https://welcometosherwood.wordpress.com/2012/06/13/screen-view-prometheus/