Most leftists hate voluntary programs on principle.
IMO, the article seems to say that a lot of progress is being made already, although I'm sure the environmentalists would prefer crippling industries at gunpoint.
It's so easy when you have no financial responsiblity for throwing sand into the gears of productivity. After all, it's not like they need to account for the billions of dollars and lost jobs. It's like being able to take a baseball bat into a china shop and go nuts, knowing you'll never have to pay a nickel.