Are you serious? It's mandatorily configurable. Are you suggesting that Secure Boot just not be implemented by motherboard manufacturers? Or rather that Microsoft should just pretend it doesn't exist?
Secure Boot is quite a useful part of the UEFI specification, albeit maybe not in the average case. I should hope it doesn't get ignored just to satisfy conspiracy theorists.
The most dangerous malware is now produced by states.
If RedHat and Ubuntu can pay their us$99, I guess NSA, BND, CIA, Mossad and others can also. So secure boot is not adding any security, imho. There was already the case that Microsoft implemented a backdoor in NT export versions for NSA 13 years ago.
There was conspiracy theory speculation that they did so, if it is _NSAKEY that you are thinking about, but few competent cryptographers or security researches took that seriously. Typical responses were like this: http://www.schneier.com/crypto-gram-9909.html#NSAKeyinMicros...
> It shall be possible for a physically present user to use the Custom Mode firmware setup option to modify the contents of the Secure Boot signature databases and the PK.
Anyway, the latter claim is purely conjecture. Why would they change convention once everyone has already implemented all this standard/custom mode stuff that they require for 8?
That is exactly what Microsoft mandates for secure boot for Windows 8 certification. Please stop spreading misinformation.