Right, so after my friend made his remarks which led me to write the top level post, I realized that from a certain point of view Hawking's remarks are accurate.

That being said, Hawking's remarks are very much prone to being taken out of context and being used in misleading ways. See for example the video in the ABC News article.

I believe that prominent scientists should take special care to qualify and elaborate remarks that sound sensationalist, because if such care is not taken, then there's a very high probability that upon being repeated the remarks will have the effect of misleading the public, contributing to general low levels of rationality by lending scientific credibility to science fiction. This promotes the idea that science is on equal footing with things like astrology.

In general, I'm very disappointed that Stephen Hawking has not leveraged his influence to systematically work to reduce existential risk. Though he sometimes talks about the future of the human race, he appears to be more interested in being popular than in ensuring the survival of the human race.