It's not a speech on how "humans are terrible". He's putting things into perspective, echoing similar thoughts to some of the astronauts that have seen Earth from above - that we need to work together to preserve our fragile (in terms of human survival) planet. The view of the astronauts is similar to the view of Sagan - a sudden realisation of how small we are. Not because some rocks and space are bigger, but because we're so similar and so close to each other in the vastness of space.

You're ragging on it being emotive as if that's a bad thing, completely and utterly missing the point of what he is saying.

Edit: it's not so much that you're missing the point of what he is saying, but I think you're severely underestimating the power of emotion in argument. I see it constantly on tech-oriented discussion sites.