They even changed the CPU at some point. It used to be ARC, now it's SPARC. The LOM aspect of it didn't change. It worked just fine with ARC before. So why did it change?
There is no technical reason why implementing the LOM function is easier or better with one CPU compared with another. In fact, there's no technical reason why implementing anything is easier with one CPU or some other CPU. The new CPU seems even less power-efficient than their old one. The only reason why you'd want a particular CPU architecture is if you want to run some particular code for that particular CPU. And apparently running this secret code is so important, that it was worth the huge expense of porting all the other already-existing, already-working firmware they had before.
http://recon.cx/2014/slides/Recon%202014%20Skochinsky.pdf
SPARC and Java(!) are present in this system. It gives a whole new meaning to the "3 billion devices run Java" advert...