The precautionary principle is objectively bad? That's a massive assumption that only holds if you are somehow confident that nuclear war, engineered pandemics, advanced AI derailing society etc. are all impossible, right?
To see the other perspective, try replacing "consumption" with food and "consumerism" with obesity. We only have 1 earth (for the foreseeable future), and rampant consumerism leads to a very inefficient conversion from its resources to value.
Also, you can still be anti-consumerism while agreeing that the global south would ideally see higher consumption. Reducing obesity doesn't mean we shouldn't feed the starving.
This works both ways imo. You can boldly state things in a manifesto, and people can boldly criticize it.