Agreed, but they're not that complex to retrofit to a parking space. I can foresee a future where each space has a port and an account card reader - they'd make the buildings more valuable, the supplier to that space has a basically guaranteed income stream, and the government has an easy emissions reduction. Wins all round, so why wouldn't it happen?
The operator could demand an exclusivity contract from the landlord, provide faulty equipment, then charge high fees to repair it, eventually leading to many stalls non-functional until the contract is invalidated in court or the two parties settle, the chargers are ripped out, maybe with purposeful permanent damage to the wiring to make it unusable, and another mildly more honest provider comes in and does something slightly better but not by much.
Or, an enterprising landchad could realize they can charge 10% more kWh than people actually pull (blaming efficiency losses), along with a healthy margin for "maintenance".
Sure, it's a market with massive abuse potential, but we have a world full of them and we regulate to control the abuses. The underlying service is clearly of societal benefit and would clearly be profitable to all parties, so it's worth doing and working out the regulation to make it viable.