Franchises never know when to quit. It's not their fault. It's the way they're made. You liked the first one, so naturally you'll like the second. If you lined up for two, you'll want three. Before you know it, the aging action hero has been trotted out seven or eight times, and we're still queuing up, expressing hope this installment will be better then the last. "I liked one, two and four. I'm hoping this one is as good. The last one was terrible. The one before that was OK..."
Now, there are certainly some stories that are more deserving of an extended cinematic treatment. "Harry Potter" and "Lord of the Rings" had the material. So do comic books and spy thrillers, though one runs into the problem of actors aging faster than their heroic counterparts do.
Strangely though, we don't get the ongoing adventures of George Smiley, John Carter, or Jack Reacher (though Tom Cruise is keeping his fingers crossed on that one). We get Rambo. Paul Kersey. Rocky. John McClane. Harry Callahan. Indiana Jones. Jack Sparrow. Agents Jay and Kay.
In all fairness though, Captain Jack Sparrow and the Men in Black should have been able to sustain franchises a bit longer. Their universes are expandable. Yet they stagnate thanks to the Hollywood mentality of making it bigger, louder, and dumber. With stories like these, I think it might benefit the studio to go smaller in scope. The Men in Black could have had a movie (or two!) where they enjoyed a grittier and grubbier investigation, as in "The X-Files." Jack Sparrow could have just raced Barbossa to the Fountain of Youth, and not the entire ocean and all its monsters. Wouldn't it have been great to have just had "For A Few Dollars More" type of pirate film, with two pirates stripped down to their essentially greedy nature, instead of combating crown, country, Blackbeard and mermaids and everything else imaginable?
That's one reason franchises can't sustain themselves. The other is a factor of time. If enough passes, the characters become irrelevant. Enough time has passed between the first "Men in Black" and the third to render it a cultural relic. An entire generation has been born and come of age since 1997. Sure, they've probably seen "Men in Black," but there's probably a good chunk of kids who haven't. Why would they line up for a movie full of characters and in-jokes they don't know? This is a universe you'd have to stop and explain to them. A franchise is dead when it has to stop, and explain itself because it's been away too long.
Franchises also need to stay within their zeitgeist. "Men in Black" is actually a perfect example of this. The 1990s saw a big revival of aliens and conspiracy theories, as evidenced by both "Men in Black" and "The X-Files." And why not? The economy was good. The world was (relatively) peaceful. We had time to wonder about shadowy government organizations and UFO cover-ups, whereas now we get actual news of cover-ups and unmanned drones, so our fantasies are rendered a little embarrassing.
"Men in Black" isn't the only series to do this. John Rambo just didn't make any sense once he was kept fighting throughout the '80s and '90s. He's a Vietnam ghost, not a military savior. Rocky didn't either – though there is some tragedy to be wrenched out of a scrappy underdog life then being thrust into a pay-per-view world, it just didn't really work that way. Harry Callahan and Paul Kersey were both born out of a very specific 1970s crime wave that rendered them supremely awkward once we were satisfied justice was being done. No longer representative of forgotten victims, they started shooting bigger weaponry to keep us sated. It didn't matter that we didn't need them to, we just wanted to see it. We get rather gladiatorial about our gunslingers, and it's chilling.
And if they made another "Dirty Harry" (or "Lethal Weapon," or William Shatner headlining "Star Trek," or ten more "Die Hard" movies) we'd line up. And why? Shouldn't a franchise end when the heroes it portrays are actually too old to do their job? Cops and captains do eventually have to retire. Why do we want to see an 80-year-old McClane or Callahan out there, huffing and puffing, unable to catch a suspect because they would break a hip? This problem also plagued poor Indiana Jones, who now has grayed past the era when he doesn't have to fight fascists for artifacts and into an age when he needs to stay home, and write academic papers to keep his tenure.
Franchises should die for all of these reasons, and more. Few tales can truly support ongoing cinematic installments, and the ones that have (Harry Potter, James Bond) are the bizarre exceptions to the rule, cherished because they retained their cast and charm, or have improbably survived reboots and rotating faces. As we head into an era of fresh franchises – Marvel, DC – we ought to remember what we hated about constant revivals, and be mature enough to say good-bye when they hit the point of old, weary irrelevance. When they're throwing everything at the screen in the hopes you won't notice the gray hair and repetition, then it's time to play them off, don't you think?