Prometheus - great story, good characters, enough Alien references to excite die hard fans and a plot that needed to be expanded and explored in the upcoming sequels.
Alien: Covenant - horrible story, boring and unlikeable characters, killed off Prometheus' protagonist, more emphasis on the androids, completely ignored important questions and plot lines from the first, also included aliens.
"See, the Alien has ran it's course, it's not scary anymore, that's why it did really bad at the box office"