Saying "this would be good for power line inspection drones" is true, but think bigger. Imagine if you could operate a fleet of delivery, surveillance, _whatever_ drones, with an already in place, widely distributed charging infrastructure that costs you nothing to build (but you pay for usage).
This is like in-flight refueling massively extending the operating range of jet aircraft.
You don't even need many drones for surveillance, just a few ones that deploy mini cameras using power lines both for power and communication. Cameras wouldn't need a battery to operate because they'd remain in place. No drive logic, no sensors, no motors, no batteries: much cheaper, just leave each one at regular distance and collect information remotely.
I should have probably left surveillance out because I was thinking less about panopticon style surveillance and more things like traffic patterns, crop growth, etc.
IT could have also less malicious uses, like wildfire monitoring for example. A 360 degree thermal camera hanging from a line would allow immediate warnings about the surrounding area long before some human notices.
You're only thinking of the near certainty that a ubiquitous surveillance state would lead to government corruption, mass incarceration, general anxiety, the disruption of norms, and the end of many civil liberties. Try to focus on the upside potential for a small number of investors!
This is like in-flight refueling massively extending the operating range of jet aircraft.