Tim Holt's got a post up on his problems with ed-tech conferences, mostly revolving around cost (they should be free!), size (smaller!) and target audience (not the already converted).
I'm sympathetic, but I don't think he quite hits the mark.
I think the core problem is less with how conferences are run and more with ed-tech's dependence on conferences, because other routes are just weak in this field. The journals don't seem very influential, the academic programs seem weak, the market is unresponsive and opaque, even online sources are still underdeveloped. We depend on conferences to do more than we should require of them.
Beyond that, I think Tim gets the relationship between national and regional organizations and the conferences they host backwards. As far as I can tell, a lot of these organizations practically exist to manage these conferences. The idea that they could hold them for free implies that they have some other significant source of income which could underwrite the conferences. I don't think so. I think these organizations primarily make their budget by holding the conferences, and without the conference, they wouldn't really exist.
We don't need to try to drag non-technical teachers to ed-tech conferences. We need better professional development in schools. We need, for example, lesson study.