With the sleeper hit “District 9” behind him and “Elysium” coming up, Neill Blomkamp seems to have acquired the perfect cachet to take on a franchise tentpole. His stories have a strong social conscience combined with exciting action and visual flair. He hits the sweet spot where serious meets fun.

That inspired speculation he’d take on a studio franchise, especially “Star Trek.” His resume, after all, seemed especially perfect for “Star Trek,” which has such earnest roots.  Yet Blomkamp recently told Filmz, a Danish website, he wouldn’t do the next “Star Trek” movie. (Update: Paramount says Blomkamp was never offered the next “Star Trek” picture.)  Though he was a fan of “Star Trek: The Next Generation,” he said, he didn’t want to deal with the politics of a franchise feature. “Would I be able to make the’ Star Trek’-film I want? Probably not, and therefore I have no desire to make it.”

Fans may be disappointed, but Blomkamp made the right decision. He’d actually be an awkward fit with Gene Roddenberry’s earnest sci-fi legacy, and he seems to know it. His approach to science fiction is too personal.

First, there’s the basic matter of creative control. A franchise installment for “Star Trek,” superheroes and “Star Wars” must must generate toys, games and lunchboxes. That means the studio’s licensing and marketing people are never far removed from decisions about design and story. For many directors, that would be a happy trade-off. Blomkamp doesn’t seem to be one of them.

“I’ve seen some insane, absolute dream projects come across his table,”  “District 9” and “Elysium” cinematographer Trent Opaloch, a longtime Blomkamp collaborator, told Variety. “Studios that have thrown this stuff at him, huge opportunities,” says Opaloch. “It’s just not his thing.  He’s not interested so much in the ‘Star Wars.’ … With Neill, knowing him as I do, the default (answer) is ‘No, why would I do that?’ He’s got a channel for telling his own stories with his own characters. And that’s just who he is as a person. I think that’s really really cool. It’s pretty inspiring, actually.”

Second, while Blomkamp’s mix of issues and action seems just right for Capt. Kirk & Co., there are some crucial differences. “Star Trek” has always been a mix of pulpy sci-fi (ray guns, telepathy, green-skinned alien seductresses) and earnest social commentary. Roddenberry created the original series because TV censors of the the 1960s wouldn’t let him write about burning social issues in contemporary-set dramas unless he set his stories in the 23rd century.

Even the movies carried that issue-orientation forward. Wags labeled “Star Trek IV: The Voyage Home” as “Star Trek saves the whales,” and the original cast’s finale, “Star Trek VI: The Undiscovered Country,” amounted to our heroes emracing Gorbachev and the reformers in the Soviet Union. While such social commentary was missing in J.J. Abrams “Star Trek” feature reboot, it was present in “Star Trek Into Darkness,” which tackled the issue of assassination by drone.

In “Elysium,” Blomkamp envisions 2154 as a time when the haves live in luxury far above the Earth while the have-nots live in misery on the surface below, a premise that even echoes a 1969 “Star Trek” episode. With “District 9” and now “Elysium” he has bolstered sci-fi’s social conscience while avoiding “Star Trek’s” preachiness. But he arrives at his stories by a different route. He says he doesn’t plan a movie about this issue or that issue, the way a TV writing staff might. He writes about the topics that interest him “for whatever reason,” he says. “It can be totally unrelated to film. I don’t go about trying to inject socially relevant stuff into the stories. It just seems to naturally happen.”

Then there’s the balance of issues and action. Blomkamp has a knack for making thought-provoking popcorn movies. He likes”cars exploding and gunfire” as much as anybody. “Those are ingredients that when I was a kid, I wanted to get into cinema,” he said.  That leaves him constantly choosing between two sides of his nature. “When the ‘science fiction’ outweighs that portrayal of contemporary life through a different lens and you’re doing it for the sake of science fiction, then for this particular film, it’s wrong,” he says. “That’s what I was constantly balancing. You know, where this science fiction, R-rated, shit-blows-up filmmaker wants to go right, but the allegory needs to turn left. Those were the decisions where it was like, ‘I really want to do this, but will I lose the audience because now you’re making something that’s not grounded,’ you know? That’s what I was dealing with.” In “Elysium,” the allegory won out.  On a studio tentpole, he’d be under enormous pressure to favor action.

Finally, there’s a crucial difference between “Star Trek” and Blomkamp’s science fiction:  Blomkamp writes about a future where the social ills of present-day Earth are exaggerated; that’s how he shines a light on today’s issues. “Star Trek” imagines a future where Earth is a utopia; it’s the aliens and off-world colonies who have the social ills. “Star Trek” was also quick to serve up pat prescriptions for those social ills. Blomkamp doesn’t. Though Variety critic Scott Foundas wrote “‘Elysium’ offers “one of the more openly socialist political agendas of any Hollywood movie in memory, beating the drum loudly not just for universal healthcare, but for open borders, unconditional amnesty and the abolition of class distinctions,”  Blomkamp himself says “I genuinely am not sure if ‘Elysium’ has a message.

“These are observations of mine in a highly complex world that has proven to be unable to solve these problems, going back to Mesopotamia,” he said. “It’s just human nature. So these are my observations with a science fiction filter over them. I think for a message, you have to be able to provide an answer. It’s kind of like saying, ‘Do this,’ or ‘Think of it this way.’ I just simply don’t have the ability or the information to do that. I don’t have an answer. And I think if you don’t have an answer, all you can do is show the audience contemporary life on earth from a different perspective.

“I think that filmmakers that really think that they have a message and they think that they’re going to change the world are sorely mistaken,” he says. That, more than anything else, probably makes him the wrong man for “Star Trek.”

So let’s not lament Blomkamp’s decision to board the Enterprise. He’s building his own legacy, his own way, and we can all look forward to what he does next. Even if it doesn’t inspire lunchboxes.