As regards ECUSA's hemorrhage, there may be an element of exit from church life, but my observations (experiences) say that may be a smaller percentage than is apparent. I suspect many arrive at their "destination" in protestant churches rather quiet about their church history, and so it goes unnoticed.
From this blog it seems many aren't arriving in the Continuing churches.
I've wondered about that, too. You're right, since in most of the evangelical churches, especially the very popular mega-churches, one's prior history is of little interest.
You know, it's also interesting, when I think about it, a lot of the Continuing Anglicans I knew didn't grow up Anglican. Most of the clergy did, but a sizable proportion, if not a majority, of the parishioners had wandered their way in from other Protestant churches looking for the historic church and liturgical worship. Do you find this to be the case, or was this an isolated experience?