The problematic part is if they choose to shut out other players without any better reason than wanting to dominate the market.
Free markets aren't infallible and they can quickly become unfree when moats have been established. (Amazon feels like the obvious example of that. Competing with them is close to impossible.)
You aren't just buying a car with Tesla, you are buying an ecosystem that just works.
Legacy automakers had almost a century to create this network. And look at the current reputation and state of their dealership network.
This is the key.
You can just punch in a destination in a Tesla, it'll map out the correct route with chargers. Other cars can usually do this too.
The car will pre-heat the battery for optimal charging temperature before arriving at the charging location. Not all EVs do this, they should. Cold-gating during charging is a big deal when traveling long distances in below freezing temperatures.
A Tesla can also check if there are free spots in the charger. No other car does this as far as I know.
Inasmuch as GM had responsibility to help build Tesla’s supercharger network, I agree.
The fact that an SV startup managed to build itself what might be considered a moat by some regulators in a few years while being laughed at by the legacy carmakers is very ironic.
If they think they can build a better infrastructure, they should. That's the free market.
I bet they can't, worst case Tesla can always buy these charging locations at a discount.