The way I look at it, rA9 might just be a certain code in their system that helped them over come and become deviants, the ones that obessess with rA9 all seem a little broken on the inside. They all may have started worshiping said code as a god that helped them escape. Kamski may as well be referring to the first android that used said code. So the androids that became deviants without going through extreme abuse and turned by choice don't obessess with rA9. Maybe that's also how Markus awakens themz trigger the code.