centuries to break down and decompose, littering all over considered part of the progressive agenda? Reducing waste is just a progressive thing? This doesn't seem to have much, if anything, to do with global warming. I imagine some conservatives would take issue with that idea, that only progressives care about excessive and environmentally-harmful waste.

And on that topic, isn't this exactly what conservatives would want? Rather than government outlawing the bags, this is a business choosing to work towards a solution for a problem that affects everyone. If people hate it, they choose to shop elsewhere.