Replacing plastic straws with paper straws is at best little more than greenwashing (and honestly, possibly even worse), since the environmental effects are so minimal. Contrast this with plastic versus paper bags, where plastic bags due to their extremely light weight have a much greater tendency to become windblown litter, so they do have a comparatively greater impact on the environment.

One of the real problems of greenwashing is that it's trying to sell an idea that with just a tiny, almost unnoticeable change to lifestyle, you can keep doing what you're doing and still have the peace of mind that you're not doing anything bad for the environment. Plastic recycling falls into this category--oh, just recycle this thing instead of throwing it away, that means there's no more guilt to be had over the environmental costs of plastic production (meanwhile ignoring the fact that plastic recycling is largely nonviable and so all of that goes straight to the waste stream anyways.)

The hope is that in the alternative world, instead of praising companies for taking what are ultimately only token steps towards environmental stewardship, we'd actually castigate them harder and get them to take real steps to improving the environmental aftereffects of their activities.