Their excuse is that it's "saving the environment"...it's not really.
Guess what percent plastic bags make up of the "waste stream".
I think grocery stores should say "we're milking this environment thing for all it's got, and squeezing just that much more money out of our customers. We like money, people, and getting an extra ten cents per bag, with all the customers going through here...score!"
I'd commend their honesty.