The issue I have is companies like Google and Puri.sm have asked Intel and AMD for a blank signed blob that completely disables ME but they have refused this. It would take them literally no time at all. This raises all sorts of red flags that something dodgy is going on.
If you had the chance to make a supplier who creates millions of chromebooks happy, wouldn't you take every opportunity to help them, especially if it costs you little to no money at all. Obviously there is a big reason why they don't want this backdoor removed.