It's not really a mystery if you understand who the customers are. Tesla's Supercharger customers are Tesla owners (for the most part), and Tesla has a vested interest in keeping them happy.
Other charging stations are mostly installed in mall parking lots and so on by government mandate. The owners of the parking lots pay to get them installed and maintained--they are the customers. And since they're (mostly) satisfying a government tick box, there's not nearly as much incentive to keep functioning.
Other charging stations are mostly installed in mall parking lots and so on by government mandate. The owners of the parking lots pay to get them installed and maintained--they are the customers. And since they're (mostly) satisfying a government tick box, there's not nearly as much incentive to keep functioning.