I absolutely hate when movies dont wrap themselves up and do that shit where they let you "assume" what happened. Well next time I hear a movie is like that I will just assume the plot of the movie instead of forking over money to see it.
People thing its fucking artsy, I call it lazy. The ending is often times more important than the rest of the movie, and I think when scriptwriters take this route, its simply trying to play it safe and not put in an ending that might piss people off.
I disagree with this.
I think departures from "the heroes journey" can be quite refreshing.
One example that comes to mind would be some of the films that John Carpenter has directed. They Live has a climax to the film, but then opens up a whole other can of worms due to it. It lets a creative mind imagine what the outcome could be, rather than it being an inept screenwriter (there are shit screenwriters out there-- and there are shit movies).
More or less, the blockbuster changed everything. It really goes to 1975 and Jaws-- and the revival of commercial cinema.
http://siskelandebert.org/video/GOMS2W8D52M9/Siskel-amp-Ebert-on-Chicago-Tonight-1998
Go to the 4:00 mark. It is wrapped up succinctly.
I have seen this problem that you pointed out with student scriptwriters. They want to get to a certain scene in a film and will sacrifice the rest of the script (quality-wise) to get to that scene. I've always said, if you have a good scene-- film it, and call it that.
I have step outlines for features I plan to write later this summer. What I will do is call 3-4 other writers and set up a workshop to help shore up holes in the writing. I think many writers do themselves a disservice by being the only eyes on their script.
Sometimes you're screwed anyway, because when a company buys the rights to your script, what you see on the screen is a 180 compared to what you originally had on paper.
I have been indoctrinated into the "style" of how you should write a film. I can sit in a room with you and tell you how 90% of films will end by the 15 minute mark.