'Yes, Episcopalians, and Anglicans in general, seem to embrace the ideals of congregationalism (the mentality that says, “As long as my parish is okay, I don’t care what happens on the national level.”). But even that doesn’t stop people from continuing to stream out.'
Most lay Episcopalians do not embrace the concept of 'congregationalism' for theological reasons. The problem is that they cannot take off all the time to go to all these conferences, retreats, diocesan, national, and international meetings. These national and international structures and alliances seem remote. Lay people can identify with world-wide Anglicanism, or with some ‘network’ or ‘council’ till they are blue in the face, but if the local parish does not offer anything that is even remotely satisfying, or if the local parish priest is lazy, incompetent, or in-your-face constantly with his or her revisionistic views, they begin to fall away, one-by-one, family by family. The geographical location of a suitable alternative then becomes a top priority. If you live in a huge metropolitan area, driving for over an hour is just not acceptable (or affordable, given gasoline prices.
Our former rector was (and is) very confrontational and in-your-face (funny how these supposed apostles of "tolerance" are absolutely intolerant of any disagreement with their view of what constitutes tolerance . . . )