My understanding of things like the IME is that its reason for being is mostly benign, it lets enterprise-level IT departments do things like boot computers from across the network and stuff like that. It has no real use to home customers on their private PCs, but it's included on all systems to simplify engineering; it handles a lot of the early boot process. And it's always running. The privacy enthusiasts out there who carry a copy of TAILS on their keychains just in case aren't fond of the fact that there's a proprietary OS with unrestricted access to memory and networking just sitting there with no way of auditing or monitoring what it was doing.

This has been a thing for AWHILE now, and the whole coreboot thing...Intel, board manufacturers etc. keep their data so locked up that it's a challenge to build anything that works, so it's a miracle we have things like Coreboot at all. They largely concentrate on laptops IIRC, and it's rare to see full fat desktop motherboards that work with Coreboot.