It's used to remotely manage almost all aspects of the computer; it's a parallel, out-of-band subsystem, complete with its own processor, memory and OS.

It's very useful for managing computers at scale and at physical distances. Imagine making changes to thousands of computers; manual, one-at-a-time, hands-on solutions are very inefficient and error-prone. Imagine a campus or office building where the average distance from the IT support office to the computer is 20 minutes. Staff can spend most of their time in transit: 20 minutes there, 10 minute fix, 20 minutes back. 80% of the IT labor budget is paying people to walk.

But I agree; there's no reason the computer's owners shouldn't have the power to disable it if they choose.

Consumers have also shown zero intention of paying more for secure devices. Until we have a public ME hack with real consequences, I do not expect that to change.

Unless you have a fuse to be pulled, or blown.