Except that loose carts roll away and get blown by the wind scratching other people's cars. Carts put up on curbs and in gravel etc. ruins the wheels making everyone's experience worse. Carts left in the parking lot block spaces so people can't park in lots that already sometimes are overfilled.
You're not 'sticking it to the man,' the store owner or corporate shareholders who make the rules and set the prices don't care, you're making life worse for your fellow shoppers.
Trump: makes incorrect claim
Moderator: Actually there is no evidence that happened
Trump: well I saw it on TV! Someone said it on TV! Someone wouldn't just go and say something on TV if it wasn't true!
Shouldn't the president of the country have a bit of higher standard of evidence than "I saw someone say it on TV"?