@maxdancona,
You are quibbling with the term "gratuitous" and attempting to apply it too literally.
I believe the intent of the use of "chickenshit" was to ensure that the movie received a PG-13 rating. I don't have proof of this, but haven't looked for it either. It doesn't really matter, though, whether the purpose was commercial or simply quirky self-indulgence by the film-maker, usage of the term "gratuitous", in the context of this film, is accurate and not contradictory.
You need only view the clip I've linked to form an accurate opinion (which would only be reinforced by viewing the entire film) that "chickenshit" and similar words are not part of the character Phoebe's usual vocabulary. This is the one and only time she uses profanity, and none of the other older children in the movie (her family and friends) ever use profanity. I can't be certain, but I don't recall that an adult in the movie ever uses profanity. This is in no way a case of "keeping it real," nor does the movie contain a series of non-sequitors for the sake of humor.
In the movie [url]Scent of a Woman[/url], Al Pacino's blind character dances a tango with an attractive young woman. It is the best scene in the movie, and in my opinion, one of the top 100 scenes of all movies. If during the dance the woman's dress somehow rides up and reveals that she is not wearing panties, or one of her breasts is exposed, we would rightly consider the nudity of such a scene gratuitous. Even if we learned that the director intentionally included that aspect of the scene to boost ticket sales or simply because he wanted to see the actresses breast, it would still be gratuitous.
When we were first married, my wife and I lived in a federally subsidized apartment complex. The vast majority of our neighbors were fine people, but as you might suspect, few of them had gone to finishing school or worried about the proper use of
who vs
whom.
One morning as I was walking to my car I approached a couple of kids who were probably no older than seven . They were engaged in what seemed to be a fairly serious conversation of which I could make out nothing. As I passed them I heard one kid in a soft and sympathetic manner say to the other
"Ain't that a ******* shame."
It is not difficult to imagine a film where that line of dialogue delivered by a seven year old actor would not, at all, be considered gratuitous, and assuming artful treatment and accepting the likelihood of additional use of profanity, I might very well have brought my own young kids to see such a film.
I don't think anyone on this thread has flat-out objected to the use of profanity in films. I certainly don't. And while you are correct that profanity is often an effective and appropriate device for writers, it can also be a crutch for lazy or sloppy ones as well. It can also, as in the case of
Monster Squad, be gratuitous and reflect poorly on the skills of the film's makers.