Not really sure why companies hurt themselves in this way.
The founder has a software background, and built out a software service to track energy usage and deliver data-driven pricing plans. But when he tried to sell it to the energy companies, it didn't find much demand for the software. So they setup their own energy supplier to prove how good it was. They now sell their software in mulitple countries.
As a customer, not only can I get an API key and retrive usage data. But I can also use an API to see what other pricing plans are available. And in the mobile app I get to the minute usage reporting.