While I'm pleased to see conservative groups leaving the mainline churches for more orthodox groups, I have to ask, what took them so long?
Groups like TEC and PCUSA have long since lost the marks of being a true church in the classic Protestant sense of the word. The mainlines have been compromising on much more fundamental issues than gay rights for a long time. If someone like Bishop Spong in TEC or Bill Phipps in the United Church of Canada can deny the Gospel with no sanction, that ought to be a final straw.
That was always my question, too. I know a few ACNA people, and I asked them, "Oh, so Bishop Spong can deny the Gospel and keep his job back in the early 90s, but you ordain just one gay man, and now it's the end of the world?"