Novel explains it better... he contemplates that his body actually matters in a sense that he has done so much work for it already and spent so much resources, that it would be difficult to build it again with Earth's scarce resources. He can't just go rampage and discard his body.
the guy in black should just shut the fuck up "IT CAN NOT". You dare argue with him knowing he can kill you in less than a millisecond? Wtf man you're playing with your own life at this point.