Yes, there are many people who blog and otherwise publicly discuss development methodologies and what they’re working on, but there are even more people who don’t. Blogging takes time, for example, and not everyone enjoys it. Other people are working on commercial products and can’t divulge the inner workings of their code.
That we’re unable to learn from the silent majority of experts casts an unusual light upon online discussions. Just because looking down your nose at C++ or Perl is the popular opinion doesn’t mean that those languages aren’t being used by very smart folks to build amazing, finely crafted software. An appealing theory that gets frantically upvoted may have well-understood but non-obvious drawbacks. All we’re seeing is an intersection of the people working on interesting things and who like to write about it–and that’s not the whole story.