Jane10, it's funny, but I read your title totally the opposite way. I do feel the retailers DO have a responsibility, to cut down packaging waste as much as poss- and that we should support them. Bio-degradable bags are made out of maize- and it takes 1000s and 1000s of acres of land, fertilisers, etc, to produce, so not that good really.
Where I live, supermarkets sell re-usable paper bags- but I always take my own heavy gauge bags for food shopping- and I have 2 large cloth bags which I wash from time to time for clothes shopping- easy peasy.
Kitty, the thought of John Lewis wrapping glasses with lots of bags seems so daft and wasteful- why don't they use tissue paper???
I used to get funny looks and even been told it was not allowed to buy M&S and other clothes without using their bag- but I always insisted and said I'd keep the receipt handy if stopped by store security.