> That's why environmentalist organizations like the Sierra Club support infill development
Except the Sierra Club in SF, which strongly opposes dense housing.
The modern Sierra Club's motives are political, not environmental. That's why they'll have rallies in SF against oil development in the Dakotas while remaining completely silent on groundwater poisoning right here in CA and the fact that (unlike the red oil states), CA has no oil extraction tax.
This bill specifically applies to development in urban areas only. More development in areas that are already urban will reduce pressure for cities to expand outward, into pristine wilderness. That's why environmentalist organizations like the Sierra Club support infill development: it's a low-water-use, low-greenhouse-gas alternative to suburban sprawl.