Trying to keep up with web development trends is a full-time job. I don't mean that as hyperbole and anyone that is actively engaged in staying on top of emerging trends in web development knows how difficult it can sometimes be.
The developers actively involved in creating the new frameworks and defining the new meta-patterns aren't always helpful, either. Some web development communities—lived out largely in the form of forums and mailling lists—can be irksome to beginners and visual learners. Many developers feel a "you should be able to figure it out by reading the source code" attitude in that community. This deters many people from trying to learn these new patterns. They wait until there is a critical mass of developers and industry attention before taking the plunge. But this presents a software community with a classic catch-22: they need users to test their code but they can't get users because their code isn't tested. The process of accumulating enough users of a framework, including the essential bloggers, tutorial writers, and industry OpenSource "patrons", can often take four or five years—sometimes longer.
This was the case with MVC (Model-View-Controller, for those new to web development) just a few short years ago. I remember going to a Java user's group meeting where Spring (during the 1.0 timeframe) was presented and I was excited. I liked how the framework was put together and it was such a pleasant alternative to hooking servlets and JSP pages to EJBs. I was so opposed to using the "accepted" J2EE methods, in fact, I wrote my own XML-based framework from scratch rather than subject myself to the overhead and complexity of a J2EE application.