Putting shopping carts away is bad for society and you should stop doing it.
The reason is that putting a shopping cart away requires labor, labor requires a person to do it, and the person who has to do it is employed by the grocery store.
Thus, if enough people refuse to put their shopping carts back, enough excess labor will be generated at grocery stores around the country that they will be forced to hire more people to do it, creating jobs.
QED
This is also why you should grab and distribute random objects while shopping at the grocery store. A bottle of canola oil by the diapers isn't rude busywork-making assholery, it's praxis so good you'll need to rush out of the store as soon as you're done so as to avoid a deluge of grateful employees' kisses.