Your arguments are almost childlike.
Almost? Just almost? I was aiming for completely.
But seriously, would you take a 1DX to Antarctica for that once-in-a-lifetime, all-important assignment, knowing the camera is not rated for that environment?
Edit - I'd take a 7D too if I had to. I find Canon bodies to be very reliable and robust. My mate trekked the Himalayas with a rebel T2i with no issues (the kit lens might have taken a few knocks though!).