I don’t think so. These things actually happen all the time. However, you’re free to not “think of the children”.
There is fearmongering and actual problems. and i think this one is legitimate. At the end of the day a car is dangerous heavy machinery. At speed it can do all kinds of damage and kill several people at once. And even without being running, it’s a 2t heavy metal thing. it can still easily crush people, your neighbour’s dog and put dents into their car / home / mailbox. Or you can leave your toddler unattended and cook them in the sun. Idk kids and cars aren’t the perfect match. And if you own or operate heavy machinery like a car, you’re the one responsible to do the bare minimum to migitate for some of the risks.
Edit: I’ll give you a pass if you live on the countryside and there aren’t much people around. But leaving your stuff unlocked isn’t the correct solution for theft. Maybe stop the thieves. Or give them something to eat or a job so they don’t have to smash all those car windows. Idk. I think this excessive car theft is a thing in a few selected cities. In other places you wouldn’t leave your backpack in your car and invite someone to break your windows, but other than that there is little chance of someone damaging an empty, locked car. ( I’ve locked my car every day for decades and had zero break in attempts )