In the Tesla forums, Superchargers seem to be highly debated. Who should have access, whether the access should be included with a Tesla or not, if it seems fair that someone who paid over $100,000 for their Tesla should have to wait for someone who bought the base Model 3.
I say, for Teslas, Supercharging should be included. The Supercharging network already gives Tesla a competitive advantage over other manufacturers whether it is included or not. I think including access to it would set them even further apart from the "competition".
Personally, I think it would be wise for them to "sell" quick charging capability to people who purchase their vehicle from other manufacturers. Help turn the Superchargers into profit centers. Use the capital to build more Superchargers. Allegedly, even the Chevy Bolt is said to be DC quick charging capable, but with what? Where will you be able to DC quick charge your Bolt?
I don't believe Tesla has ever been opposed to sharing their network. No other manufacturer seems to care enough about it to "pony" up any dough to help expand the network. With as large as the network already is, there would need to be a significant buy in. Sure other manufacturers have talked about trying to create a standard, but they all seem to want this infrastructure funded by someone else. I think most of them support the idea of it being funded by the government.