No. Not only will I give a worker a better thing to do than interacting with some schmuck (this is seasonally dependent, and depends on the worker), I will impede the progress of cars through the parking lot, which is funny, and good, because I hate the parking lot. If I do this enough, I will singlehandedly force everyone to park farther and farther back in the parking lot, as spaces are taken up by uncompressed carts, walking more and more to get to the store. Minorly decreasing the revenue of the mega-chain as people refuse to drive, and increasing the cardiovascular health of everyone shopping at the store. Decreasing traffic, perhaps even decreasing car-centricity. Society would be better off, if we all refused to return the carts, and perhaps, I do not want to compromise on my moral code and ideal for a just society, just because nobody else is doing it. We are manipulated, out of our willingness to be just to those around us, into creating a collectively unjust society.
So, really, I'm like some kind of hero. Everyone should be thanking me, for not returning the carts. Everyone should be thanking me, for shitting on the street. After all, when someone steps in it, it will simply illustrate to them the injustice that is a lack of access to public restrooms. They'll intuit that, I'm sure of it, probably it would be communicated from something in the smell, if I had to guess.