Some questions for you, Justin:
A. Why wouldn't you expect educational technologists to be the first group of educators to dive into the use of social media and other digital technologies? Why wouldn't you expect early adopters to be early adopters and later adopters to be, well, later adopters?
B. What's the difference between a 'community' and an 'echo chamber?' Do you consider Manchester United fans or Lionel Trains enthusiasts or Trekkies to be 'echo chambers?'
C. Why wouldn't you expect entry into any new environment to be intimidating?
D. Why wouldn't you expect any large, complex, self-organizing network - including the edublogosphere - to have a classic long-tail distribution, where a few have the majority of the attention and the many have less of the attention (although still valuable things to contribute)?
A couple of other thoughts:
1. You say that "Goal #1" of educational technology advocates [is] "the spreading of education technology knowledge to all k-12 educators which will help students learn." That's probably fair, although I'd say it's preparing kids for the 21st century (rather than the 19th). But your wording works. But then you go on about Twittering and blogging, which are just a couple of tools in educational technologists' arsenals. There are numerous pathways to achieving the goal that you state and educational technologists are taking all of them. So don't stereotype unfairly. Yes, those tools are popular. No, they're neither the only path nor the end goal (and few would tell you otherwise).
2. I don't speak for the ed tech field. I don't want that burden and refuse that responsibility. I do recognize that it's a harsh world out there and, in the end, no one really cares about new entrants into the blogosphere unless they add value (as perceived by others, not the new entrant). That said, the educational blogger community is one of the most generous, embracing, welcoming groups I have experienced. Time and time again people volunteer their energy, expertise, and precious time to help each other. That holds true up and down the 'authority' spectrum. So it's not that we "expect new bloggers to come to [us]." It's just that in an attention economy we all only have so much time - to write, to help, to read. Don't fault people for not having enough time to serve the world at large. This is the way the online world works. Wishing otherwise isn't going to change that reality (and, of course, the physical world works the same way). And, just for the record, a number of us try very hard to find, recognize, and highlight new voices. To be fair you should acknowledge that too rather than claiming - without any large-scale (or any at all?) evidence - that there are edubloggers who are reluctant to promote others' blogs because they're worried that they'll be crowded out of the attention economy.
Methinks that you paint with too broad a brush, my friend...