A better way of saying it would be that they just don't care that much. Most people care in theory about taking care of the environment, but that doesn't mean that they're willing to tolerate even 1c/gal higher fuel taxes. Most people care in theory about taking care of the poor but balk at the personal economic consequences of doing so. People have different priorities and when one consistently loses out to the others that means that they largely DON'T care about it.