Sorry, but other people aren't here to do what you want. They are free to innovate or fail to innovate in any way they desire. The one-true-framework has not been invented yet and probably never will be. Constant improvement and competition are what drive everything right now, and asking us to stop it is insanity.
Backbone and Cappuccino have both proven that they will last and have dedicated communities building them. All these projects need people to contribute to them and make them amazing. A core team can build it, but the community makes it a real project.
Everyone today wants to get the personal glory out of their own little pet project instead of getting the glory out of contributing important patches to existing projects.
Maybe you're right and it's personal glory. It could also be the (admittedly, often-naïve) assumption that maybe, just maybe, you have a better idea about how to do things. When John Resig [thought up jQuery](http://ejohn.org/blog/selectors-in-javascript/) five years ago, both Prototypejs and Behavior.js were already around. If he had decided to contribute to those projects instead, we'd have a much different landscape today.
Everyone? No. Most people just want to download the projects they like and build stuff with it. A fraction of those will contribute bug reports. A fraction of those will contribute patches. A fraction of those will contribute feature pull requests or plugins.
I think the perceived problem is that there isn't yet a clear winner in heavy JS frameworks. I think their usage is more niche than their social media coverage would make some people assume.