Can you prove the cult will be around for decades, or is that just smug, self-approving arrogance? Or did you mean it will be around for decades, as you announced decades ago?
I can only extrapolate from history and make educated guesses.
Historically, Google "Miller great disappointment" and then search about on the web a bit to find that the Seventh Day Adventist church is going strong to this day despite the last reason for anyone to believe in the Millerite vision vanishing, it seemed. It even has long had a parochial school system similar to the Catholic system, long before the upsurge in religious schools of more recent decades. It has been shedding children who leave the slightly cultish group at a heavy rate despite all that effort put upon cradle-to-adulthood indoctrination, but still grows. Many people don't even recognize who the SDA are, but they are going strong, despite most other Christian denominations regarding them as cultish all the while and wishing they'd go away.
That's one example of something that looks like its on its last gasp of breath enduring a hell of a long time because a small core of believers needed it to.
Consider a raggedy ass bunch of believers in a nearly dying bizarre sect of Judism who were so ineffectual and few that a guy named Saul of Tarsis could go around harassing them at will. Anything they had been promised about glorious events that would justify faith was a fizzle, there was just a rumor of its great leader actually showing up naked on a beach sometime after he was supposed to be dead, but nothing else to speak of why he could ever be important emerged. Why should it be expected to endure? But Saul decided to tell people he'd met the Exhibitionist Zombie Himself, became the Apostle Paul, and you can't get rid of those irrational bastards if you live in the Western world these days. Even mighty Soviet Russia had its durge sung over it by Orthodox Christian priests it used to harass. Someone needed it to survive, and starting from few such needy people it thrived and is dominant over much of the world today.
That's another example of something that was damn near stamped out but endured a hell of a long time.
I could cite historical example one after the other.
To understand why a religion endures you must understand why its most loyal adherents will endure hardship and disappointment repeatedly without abandoning it. That task was anathema to even discuss on a.r.s., a matter of derision for anyone to take seriously on the clambake site, and isn't really all that welcome here either. Dialogue is dominated by those who wish to mock and see the falling away of less committed adherents as proof that their derision and mockery is thoughtful enough to be adequate. For a group full of people who once were insiders, it is almost like willful ignorance is the rule now.
Is there ANYONE, I ask rhetorically, genuinely interested in why The Beast doesn't die easily?
You have to understand the core adherents to understand the longevity of a religion, and why they need to believe in it.
My educated guess is that the Church of Scientology limps along in this world, at least in the U.S., even on the day I am passing from it. The only realistic ambition is to contain it to is irreducible die hard core.
[video=youtube;4DpOQDu0G_Q]http://www.youtube.com/watch?v=4DpOQDu0G_Q[/video]