If you think this is Marixsm, you're _totally_ missing the point. This is about _profit_.
Tesla is trying to make money from selling cars, batteries and solar power.
Because Tesla would always derive most of its profits from sales of the car it has a very strong interest in maximizing EV sales over maximizing profits from charging. Given the relatively low long-term cost per car required to build an effective charging network, any attempt by Tesla to exploit its proprietary network for direct profit would likely just lose sales to competition. Instead, it has much more interest in trying to build and operate an effective network at low cost.
Utilities make money by their allowed return on investment in infrastructure and, where allowed, sales of electricity.
Utilities could be willing to have public charging at cost in order to encourage EV sales and profit from home charging, but the margins are not going to be significant. For an EV driven 15,000 miles per year using 0.4kWh/mi wall-to-wheel, each 1c/kWh of margin on electricity would earn the utility $60 per year in profit. Utilities are going to be far more interested in pushing up the margins on charging in comparison to sales volume.
I also don't see how, outside of undesirable exploitation of monopoly, utilities would have an advantage over other companies. If anything, it's the equipment manufacturers who would have the advantage in the market.