My buddies and I went to Austin on a motorcycle trip and one of our bikes broke down and we had to go to an auto store for a few small parts. When we asked for a bag to put the items in to transport them to other bike and they said "we don't have bags" we started laughing and were floored when we realized that they did not in fact have bags.
Most places didn't stock paper bags either, which we would of gladly paid for. We got used to it during the week but it was some big culture shock for us. Great for locals, infuriating for travelers.
I can certainly see how it could be frustrating to be without a bag if you need to transport your items on a motorcycle (though you were on a motorcycle trip and no one had a saddle bag they could put the things in?). Extending your experience to 'travellers' at large is a bit much. I'm from one of the dozens of other American cities with a plastic bag ban(yay!) so I think I would be quite non-plussed were I traveling in Austin. :)
I've never been to a grocery store that didn't have some kind of bags, and to be honest I've never bought enough things at once from a retail store to warrant a bag, but I can see how that could be a problem in certain situations
Most places didn't stock paper bags either, which we would of gladly paid for. We got used to it during the week but it was some big culture shock for us. Great for locals, infuriating for travelers.