It might not be trivial, but you can do this w/o the ME. My understanding is that most ethernet cards support a "Wake-on-LAN" feature to turn off machines on, and from there you can trigger the machine to reboot and then netboot (by writing to its boot config to instruct whatever boots it that it should take that action).

Even if you assert that the ME is absolutely necessary for such a use-case, I don't have that use case, it isn't work the risk for me, and I should be able to disable the ME because I, as the owner of the machine, want to. (Or really, otherwise interact with it and use it for creative use-cases.)