You brought up westerns, I brought up 90's themed action movies. That was the thing back in my day. The spectacle movies. Con-Air, The Rock, Face/Off, movies with Expendables actors. They were the must see movies for teenage boys. Not anymore. Movies like Bourne have come in their place. It hasn't proven to be cyclic. But like any genre, there is always a niche crowd. They won't ever completely go away. But we aren't talking about niche crowds. We are talking about movies for the masses. And those movies are built off mega popular franchises from literature or pre-existing brands. That's why you get sequels every summer. Every now and then, a franchise crops up. PotC. Transformers. But it's hit and miss. It doesn't mean Giant Death Robots are the new thing, or the Pirates genre is back after the turd that was Cutthroat Island. The studios are capitalizing on their brand names. Avengers wasn't a brand, but a bi-product of hard work and good story telling. It's not going to always work out that way. None of the other properties really took off by themselves. Now Fox/Sony are going back to their bread and butter. I wonder what two movies are anchoring summer 2014. I think the point of the article is at what point do these movies stop becoming guaranteed money printers that we can no longer throw 200-300 million at every single one. And that day will come before the end of the decade IMO.
Okay so basically you're being nothing but cynical. Gotcha.
Also, I brought up Westerns as an antithesis to the superhero films, not as a comparison. I'm saying they can't be grouped into a genre like Westerns can be, or 90's action film for that matter. As I keep saying, these superhero/comic book movies encompass far too much to be labeled as such. If they wanted to make a 90's action film or Western out of a superhero film, they could. The superheros are just vehicles to drive stories into different genres, and they come with installed fanbases and multi-generational appeal. That's the brilliance of it.
As for the the movies ceasing to be guaranteed money...they never were. As you said yourself, the Avengers was built off of good storytelling and hard work, the same is true of Spider-Man, Batman, X-Men, etc. Now, however, those characters ARE brands, and ARE established, and have already been engrained into the hearts of an entire new generation who have grown up on these movies...literally, an entire generation. And that IS the mass public. It's not just the types of films, it's the CHARACTERS. That's the key difference between these superhero films and past fads, among other things. It's not just one random genre to the next, it's a promise of movies about these characters that you love and grew up with in different situations, it's not just going from one rip-off to the next. It's why James Bond has been so successful and superheros are the only other medium that has been able to capitalize off of that and realize that model as a viable business.
There's no way the "bubble" is popping this decade. Marvel has movies lined up to go through 2018, and a film doesn't just gross $1.5b and then go away 5 years later, especially not when it is built it off of specific characters that people love and want to see more of. Avengers, Batman, Spider-Man movies will continue on through the next decade and barring something catastrophically bad will continue to do well. Obviously every movie is not going to be a mega event, but they're going to at the very least be solid, consistent, and steady.
In addition to all of the above, it's also gotten to the point now where the Marvel brand can pimp their new movies and franchises, like Pixar. It used to be that only these historical characters could do well, but Marvel, thanks in part to Disney, has figured out a way to boost their entire portfolio of characters in the same way Pixar boosts its movies. Obviously things aren't always going to stay as good as they are now, but superhero movies will continue to be made and at a steady pace for the far-out foreseeable future.