is that this postman - an employee of Royal Mail - took it upon himself to decide that he wasn't going to deliver items for which his employers had been paid. By doing so he caused his employers to be technically in breach of contract, and exposed them to the possibility of legal action.
It's not up to Royal Mail employees to make decisions like this, and he has been rightfully suspended. If anyone wants to opt out of the Royal Mail unaddressed mail system they can easily do so.
If all of us took that action we would all be free of the piles of junk which flood through our letterboxes............and normal postal charges would be far higher.