IBM's failure to generate revenue says more about the IBM than blockchain tech.

As you say, it's impractical for most business cases - and I agree. It doesn't have much use cases in the typical centralized business case where one company owned by a small group of investors make a lot of money off of users.

It's not a trivial exercise to come up with blockchain business cases because it requires a stretch of the imagination. It's a fundamental remodeling of the structure of society and so business cases as well.

Business cases that are successful will share revenue with those that maintain the application and are profitable when desired user outcomes are met. Check out the Helium network for a great example - a decentralized network operator!

Again, completely upside down business cases than what we're used to, but it'll be wonderful for society.