Of course I am not a strict primitivist.  However, the difference in environmental impact of industrialists versus food foragers is undeniable.  Large-scale perpetual industrialist expansion is ecological suicide, even if every brick, wheel, or volt is created and used 100% green.  This is because industrialization requires a fundamental restructuring of its territory, such that the only large animals able to inhabit it are human beings.  Western industrialization also relies on monocultures for suistenance and decoration.  There is no way to avoid this except through small-scale "primitive" living (and not rural or suburban living either, but non-industrial habitation).  These are not extremist notions inseparable from sending out letter-bombs, but verifiable facts.  Restricting the territory of human expansion has been accepted ecological protection policy for--what is it--one hundred years or so?--and there have been no convincing arguments ever put forward for rescinding this policy.  

Demanding that we all abandon modern society is naturally a ridiculous notion, and one opposed to human freedom. It opposes humans' natural drive: to discover and grow.  It's also inherently self-defeating--people will inevitably rediscover modern technology, although once a unique culture with unique story-telling perspective is lost, it is gone forever.  A large proportion of the story we would lose, by giving up modern society, will be the story of our mistakes.  The damage we have already done is catastrophic.  We can't gamble that the ecosystem would completely recover by the time any new human industrialization occured, nor can we gamble that they will discover how to maintain a modern green society any quicker than we have.  Strict primitivism could add us to the list of species that we drive top extinction.  

In terms of birthrate, the rich countries are already on their way towards my alternative; however, urban sprawl and suburbanization can undo any progress made my slowing and reversing population growth.  It will be necessary to consolidate the cities, or else there will be no withdrawal and no territories available for food foraging.  Which means food-forager societies won't have the capital to promote their alternative to city living, assuming they can even exist.  Expansion will begin again.  There must be a withdrawal.  

It is also my hope that living as hunter-gatherers, or at least a nice rugged outdoorsy type camping frontier will promote a good sense of anarchy.  Huck Finn and the Widow Douglass reach a détente.  (if you don't understand this reference, read the book, you won't regret it).