Being a humorless young man, I’m driven crazy by people who actively seek out bad movies for fun; it seems like that’s a way of avoiding engaging with good art, where the correct response isn’t always obvious. So I was nervous about Best Worst Movie, whose title tells it all. Voted worst film of all time by the normally-none-too-discriminating IMDB users, Troll 2 (Scott Tobias has written about its appeal and cult for his New Cult Canon project) has a bizarre story about people being turned into plants that makes no sense literally or metaphorically, godawful acting and general freefloating incompetence. People love it very much.

I get the appeal — it’s sui generis weirdness that never lets up — but sometimes it bothers me that people indulge in the easy pleasure of celebrating something plainly risible. And yet filmmaker Michael Stephenson makes a case not just for the movie’s appeal, but also the downside of cult filmdom. Best Worst Movie is itself an obvious crowdpleaser that’ll probably find a decent-sized audience, but — fun though it is, and even though the stakes are pretty low, and no dramatic events unfold — it’s actually kind of a downbeat film overall. Stephenson isn’t just a documentarian; he was Troll 2’s child actor. By making this movie, he delves into the appeal of something he’s part of, yet was in no way responsible for the enduring afterlife of.

Stephenson begins with Dr. George Hardy. Hardy is a dentist in the small town of Alexander City, Alabama; he’s on good terms with everyone — even/especially his ex-wife — and is generally a worthy pillar of the community. But in the ’80s, Hardy lived in Salt Lake City and auditioned for Troll 2; he’d always had frustrated dreams of acting. The resulting film was so obviously worthless that Hardy shrugged it off and moved on with his dental life. Years later, New York’s Upright Citizens Brigade got in touch with Hardy and had him attend a projected DVD screening in a room where a big column obstructs the field of vision; no matter, the 300-seat-theater was sold-out many times over, and Hardy discovered, to his fascination, that for a small group of people he was a celebrity. And he began to wonder if there wasn’t some again future for him as an actor.

“Bad food is bad, and bad books are bad,” Cinematical’s Scott Weinberg observes, “but bad movies are not always bad.” Troll 2 fans love it because it’s so staggeringly misconceived that it achieves a weird purity; “you’d have to have a heart of stone not to enjoy it,” Caitlin Crowley (of Boston’s Brattle Theater) says. People’s relationship with Troll 2 is obsessive; no one who’s seen it appears to be just a casual fan. And Hardy grasps the appeal pretty quickly: he understands that this isn’t just another forgettable failed film, and he’s continually gratified when people ask him to re-enact particularly ludicrous moments. Even though people are laughing at the awfulness of his performance, it makes them happier than, perhaps, a good performance would; it hits some kind of pleasure reflex you didn’t know you had. Hardy and Stephenson end up finding their ex-castmates, and almost all are game to re-enact it for others and talk about it; they speak of it in bemused tones, as if they can no more comprehend how they got involved with Troll 2 or how it came about better than anyone else.

But Stephenson also tracks down the film’s Italian director, Claudio Fragasso, who definitely doesn’t get it. He’s proud of his film; it “examines important issues like eating, living and dying,” he explains with infinite complacency. “In Italy we call this a parable.” (What do they call it in other countries?) He knows he’s good; how does he know? “I can direct in all languages.” He’s puzzled that audiences laugh both where he intended they would and even when he didn’t; he’s outright contemptuous of the “actor dogs” who aren’t as proud of the film as he is or take it with the appropriate seriousness. They’re willing to admit they screwed up; he isn’t. He doesn’t understand that the film’s meaning is no longer the one he created for it, and he sours the mood whenever he shows up. The person most responsible for the film is the one with the least understanding of how it works.

Another person who doesn’t really seem to understand what’s going on is actress Margo Prey, who appears seriously deluded about what kind of movie she made and who enjoys it: “You compare our movie to a Katharine Hepburn-Spencer Tracy movie, and it fits right in.” Because it’s “about people.” If Prey (who appears generally troubled) is one kind of depressing, Hardy’s a decent man who eventually burns out on his newly discovered fame: some people may confess that they’ve seen the film 45+ times, but Hardy gets tired of delivering his signature lines after 20 repetitions and goes back to small-town life. And so, if Stephenson doesn’t figure out what the limitations of the so-bad-it’s-great genre are (or the limitations of an overwhelming enthusiasm for that kind of thing), he does a great job of tracing the way culture works where the gap between what was intended and how the public responded grows too large. That he manages to also convey the lives and paint affecting portraits of a half-dozen people unscathed but amused by the movie they were in that one summer — Hardy’s ambivalence is accentuated by aging actor Rombert Ormsby’s confession “Mostly I’ve wasted my life” —  is a bonus. Best Worst Movie is a classically constructed narrative doc, but it doesn’t pump up the drama through editing or even really have a story. Something slightly less than a celebration and more of a group photo, Best Worst Movie does something really compelling out of the basic elements of camp.