Now let's make the analogy more accurate: let's imagine the blast furnace often ignores the operator controls, and just did what it "wanted" instead. Additionally, there are no gauges and there is no telemetry you can trust (it might have some that can the furnace will occasionally falsify, but you won't know when it's doing that).

Let's also imagine that the blast furnace changes behavior minute-to-minute (usually in the middle of the process) between useful output, useless output (requires scrapping), and counterproductive output (requires rework which exceeds the productivity gains of using the blast furnace to begin with).

Furthermore, the only way to tell which one of those 3 options you got, is to manually inspect every detail of every piece of every output. If you don't do this, the output might leak secrets (or worse) and bankrupt your company.

Finally, the operator would be charged for usage regardless of how often the furnace actually worked. At least this part of the analogy already fits.

What a weird blast furnace! Would anyone try to use this tool in such a scenario? Not most experienced metalworkers. Maybe a few people with money to burn. In particular, those who sing the highest praises of such a tool would likely be ignorant of all these pitfalls, or have a vested interest in the tool selling.