"If we could find evidence about all them worlds what disappeared, what difference you reckon it'd make in the long run? Would it change how the train was treated? Give us any bigger likelihood of gettin' help?"

Because his main reason for wanting to find out anything is just that- the safety of the crew. It's protective on a scale he can manage. Others could focus on the bigger threat itself, and it's worth knowing, but there's a bunch of people here that need looking after, and they need their second (or third or fourth) chance.