Spring Eddy and Extraneous Romance: A Case Study
They introduce a guy who cleans out septic tanks for a living, his stalking of his ex, and his stalking of Jennie, Eddy's ex fiance. They meet cute during a car crash, blah blah blah. Of course, there's also an additional subplot including the hit man after Eddy and some random Western wear lady. The main plot: this idiot needs to avoid getting killed for crossing the mob has great narrative tension. When we see him interact with a scantly clad hitchhiker - we think "Man, this won't be good", and wonder what happens next. When he tries to stick up a bank (on free gun day) - the result is important to whether he gets away or not
However, whether some septic tank salesman gets laid or not is not. When a movie starts off with life or death stakes, taking time out to worry about whether two random folks will knock boots really is jarring. I see this in YA a lot, actually. Sure, the evil government/aliens/vampires are out to kill a girl, but which guy should she choose? The fact that these are just side characters makes the padding even more apparent. Jennie has a part to play in that we're waiting to see if she can get Eddy out of jail. Her new boothang is irrelvant.
The hitman/random chick is less jarring since it's set up as a (flimsy) excuse to get the writer out of the corner he has written himself into. I wish he'd trust the audience- I could see several ways to get Edie out of there without a paper thin romance.
A movie isn't like a novel where one can convey the love lives of every minor character in detail. A movie is a short story. Every moment must pull its own weight. When we add romance just because it's expected- the movie becomes heavy and bloated.