I've heard Hollywood compared to Vegas many a time in my career. There is no science to what makes a successful movie or they'd all be blockbusters. Different people have different taste. Why was Private Benjamin a huge hit and no one's heard of Major Movie Star (basically same concept starring Jessica Simpson?
When I worked in development I only gave 2 scripts a Recommend. Both films were made (not by us). One was on screen exactly how I'd pictured it in my mind. The other, one of the scariest thrillers I'd read, turned out to be a joke on screen.
There are so many people involved in making a movie that the script is just the leaping off point. Unless it's your script and you direct it, there's no guarantee your vision will be what's on screen. If you're reading it as an actor or as a department head, what looks great on paper could turn out completely different by the time the director, movie stars, editor, and studio execs (after a few focus groups) get their hands on it.
My advice if you like the script: trust your gut, see who's involved, do your research on them, do the best work you're capable of, and see what happens.
For more tips and articles by top entertainment industry career coach, The Greenlight Coach, visit www.theGreenlightCoachBlog.com