I've been working retail for a few weeks now. Oftentimes, a co-worker will sigh and complain about how the customers have left the store a mess. In response, I always ask them, "would you rather be unemployed?"
When your job is to clean up a mess, if there's no mess, then you have no job. If customers all cleaned up after themselves, we'd be out of a job. Also, having customers clean the store would be terribly inefficient, since they have no training or interest in doing it properly. Essentially, they're paying a tiny fraction more in cost to reimburse someone else to clean up their mess. This is not wrong, and it is not a problem.
When you go shopping, if you want to do the regular workers a favour, don't tidy up after yourself. If you want to help the management/corporate overlords, feel free to clean up the place.