Default KitKat 4.4 Edit SYS Files?

Does, anyone have the slightest idea on why we are not able to edit ALL of the android root files on 4.4? Im running CM11 but it has happened on others equally, I want to turn off the capacitive light touchkey lights via "sys/class/led/" but anytime I try to rewrite the files it tells me permission is denied. I can only edit "system" files after using the SELinuxMod app from the PlayStore and changing to "permissive" but no luck with "sys". This is TOTALLY STUPID! And Google STILL has the nerve to call Android "Open Source"!
#HOLOYOLO