Having just posted a bit on this new book myself, I find that I understand what you're saying -- but think it might be a case of "methinks he doth protest too much".
The organic/missional church is frequently confronted with those who are afraid of both this and "heresy" -- as if the Holy Spirit is not able to teach and lead competently. Perhaps it is a holding-on to the security of "history" rather than being able to have God lead us on down the road to a new place.
For many (most?) of those for whom organic and/or missional are where the Spirit is leading, it is precisely because the forms of church they have experienced have been so toxic that they must move away. That does not mean that they are going as "individuals" -- they are going as disciples of the wild Messiah. They are being gathered together so that they may engage the incarnational/missional pulse in the situation in which they find themselves.
Hirsch and Frost are not anti-church. I believe that they are not convinced that the institutionalized church that many hold to is the "right" form of church. My experience is right with them -- moving away from 40+ years of practice into something very other. And I have had to move away so that I might see clearly enough to peal away the "laminations" of the institution in order to free the living organic body.
Perhaps many forms of the church have, like Eustace, wandered into the dragon's lair of consumerism and patriarchy and numerous other disractions ... and has awakened to find that is has turned into a dragon itself. Today's fantasy world would welcome a friendly dragon that is powerful and flies and breathes fire with which to vanquish all its foes. But, again like Eustace, it will find that the Body of Christ is a human reality ... and keeping and feeding and trying to carry a dragon along a wild sea-faring journey is just not practical. And so the Dragon that was Eustace follows Aslan and submits to the Lion's claws in order to be un-dragoned and the boy trapped inside is set free to journey with his companions again.
There is much to be gained from the continuity of the church's history. But it is too easy to set up the form as an idol and find Jesus outside that door knocking....
...or so this wee abbess thinks!
...and that's about all I have to say about it at the moment. Miles to go before I'm finished packing....