The question is what they see as their business model. Part of the Tesla pitch to buy a car is access to the big Tesla super charger network.

Competing on charging networks is tough. The charging cost is determined in large parts by energy cost and rent for the space. Customers have some ease-of-use effect to get a membership at a large network, but brand reliance is low. Thus there is little to gain, but cars from all sorts of vendors blocking Tesla's chargers isn't good for the exclusivity of their brand.