It depends on which perspective you apply. Superchargers are differentiators, so much like the concept of closed network for Apple with iPhones, you would keep them for yourself. But that would relegate you to a niche.
Tesla's mission is to accelerate the transition to renewable, sustainable sources or energy, not the entertainment of a bunch of zealots with adequate amounts of disposable income to burn on you, whatever you throw them at. You can't do it alone, you can't play the Apple game with such a mission. You need to team up and open the charging network.
We are approaching the mid of the gaussian adoption curve, where most of the frictions will come. The masses need reliable cars for day use, not fancy speed demons competing with Ferrari and Lamborghini on racetracks.
So they did a great work so far, but it's time for others to follow suit, hence getting rid of the exclusivity. Sure, there will be differentiated fees, perhaps some sort of quotas and reservations as time goes by, to keep their USP up, but the areas of key focus are clear.
Just hoping they don't invest so much time on further pet projects such as the CyberTruck, which seems more tailored for 1 out of 7 billion people's demographics (Elon), than something a company laying off staff like we saw a couple of times. Tesla Semi, for instance... where are they?