I thought also Scott used the monster a bit wrong. The story was good but the monster wasn't as creepy as in Aliens.
I would find a way live past it too if it was a total new twist to the series, a new idea. But a prequel about something that we already know and not really more interesting than becoming another monster slasher film is a bit.....
I think that Ridley Scott will not just do a slasher movie. I expect much better from him.
As far as the "fear factor" for the first
Alien crature is concerned, I think you just have to have had the opportunity to see it anew. I saw
Alien when it first came out along with a friend. All I knew about it was that it involved a creature loose on a spaceship which had the disturbing trait of growing rather quickly. When the film was over, we had to adjourn to the nearest bar to have a beer and unwind. My neck muscles were in a knot from tension. Even at the end of the film, I thought for sure the cat was going to explode and become another creature.
That was a much more intense experience than it would have been if I had seen it for the first time twenty years later, after hearing the inevitable sundry comments and opinions that the intervening years would have supplied.
I had the same experience when I first saw
Psycho in a theater, lo these many years ago. If you aren't sure what to expect, the result can be amazing. These are the only two films I've ever seen which had such a startling impact on me.
I wouldn't expect the same from a new Scott treatment of an
Alien prequel, but I fully expect to be highly entertained.