The Software Freedom Law Centre's Aaron Williamson said in a blog post that there could be many reasons for the differing policies between the requirements for ARM and non-ARM devices.
For one, the PC world is dominated by Intel, which is a founding member of the UEFI. Hence, in the case of Intel-based devices, Microsoft's requirements are close to those required by this body.
Secondly, ARM devices could be locked down without any fear of customer backlash as there was no support for older versions of Windows; on the PC platform, this was not the case. Customers who did not like Windows 8 might like to load Windows 7 or XP and would be angered if they could not.
And finally, the SFLC pointed out, there was no chance of anti-trust concerns being raised with regard to mobile devices as Microsoft had a very small share of the market. The reverse was the case with the PC and Windows.
"Before this week, this policy might have concerned only Windows Phone customers," Williamson wrote. "But just yesterday (January 11), Qualcomm announced plans to produce Windows 8 tablets and ultrabook-style laptops built around its ARM-based Snapdragon processors.
"Unless Microsoft changes its policy, these may be the first PCs ever produced that can never run anything but Windows, no matter how Qualcomm feels about limiting its customers' choices."