Have you taken apart other cars? There’s a million plastic ‘push pins’ (actually push grommets) in them, too. I took the bumper off our Odyssey. Guess what it was held on with?
Your derision gets rather tiresome. Not everything needs to be assembled with a gold-plated titanium screw. Plastic push pins are perfect for many interior cosmetic trim panels, but not for holding the tires on. 21mm lug nuts are perfect for holding your tires on but overkill and a waste for securing the glove box.
In many cases, plastic connectors are cheaper, lighter, quicker and easier to use while still performing perfectly adequately. That translates to a better value for the consumer.