> What ordinary person would elect to time-travel one-way to 11:30PM on Diamond's clock, as opposed to living at 11:59PM?

Perhaps those immigrants getting on boats that are so much in the news in Europe and the US?

Things exist which did not then, but many of the problems which exist now did not exist then. Global warming, anthropocene mass extinction, discussion of a new nuclear cold war on Russia's western border - go back 10,000 years and these problems fade away, particularly ones that could lead to human or other mass species extinction.

Of course being human in 2018 seems ok to white American heterosexual makes of the upper middle class (or higher), but that is a small percentage of humanity.

The hunter-gatherer bands in the Amazon don't seem anxious to enter Brazilian wage slavery. Why should they, mining interests are currently massacring them.