I think it is amusing that your first link shows just how easy it is to disable Secure Boot, disproving the point you were trying to make by linking it...
Also if you click through to the "Windows Certification Program" you'll find this Microsoft requirement (for the Windows 8 logo program):
> Mandatory. Enable/Disable Secure Boot. On non-ARM systems, it is required to implement the ability to disable Secure Boot via firmware setup. A physically present user must be allowed to disable Secure Boot via firmware setup without possession of PKpriv. A Windows Server may also disable Secure Boot remotely using a strongly authenticated (preferably public-key based) out-of-band management connection, such as to a baseboard management controller or service processor. Programmatic disabling of Secure Boot either during Boot Services or after exiting EFI Boot Services MUST NOT be possible. Disabling Secure Boot must not be possible on ARM systems.
That article doesn't say what you claim it says. In fact it says quite the opposite.
It lists several distributions which work "out of the box" with no modifications to the system at all. It then goes on to talk about disabling Secure Boot.
It does quite correctly whine that you cannot install Windows on Surface RT hardware, which is a valid complaint, but outside the scope of this thread.
There are costs involved in preparing a Linux system, which makes many manufacturers opt to simply abandon their non-OS/Linux lines.
Also some indirect proof:
* timing: secure boot gets introduced, suddenly all Linux shops here close * M$ has a track record of abusing its monopoly
The enormous number of articles on the web shows turning off secure boot isn't always that easy either:http://www.zdnet.com/2013-installing-linux-on-windows-8-pc-i...