One of his points is the effect that space exploration has on kids. It excites them. It makes them want to be explorers too. Kids are full of imagination, they hear about people on another world and they imagine themselves doing it too. It happened with the moon landings, and it inspired kids to become scientists and technologists and to follow their own paths to exploration.
edit: despite being born too late to be mesmerized by the moon landings in real-time, I was one of those kids. I started playing with computers and writing my first programs when I was 8. I watched a lot of Star Trek and James Doohan's Scotty was my favorite character. There was a picture of Neil Armstrong on my wall. I got "Odyssey" magazines and had a book that artistically imagined what life might be like elsewhere in the solar system that I read until, literally, the cover fell off. I had an audio cassette that took you on a wild ride through the solar system.
The hope of exploring space someday is what drew me into technology.
So many years later, and I only use that technology to have arguments with other people over whether exploration is "worth it" at all. How's that for some weltschmerz?
Recontextualizing 21st century issues is key to us actually solving them, but that means we do in fact need to do things which has emotional impact on large populations. The moon-landings captured the imagination of, conservatively, half the planet, if only briefly. Mars-landings are likely to be similar. And an ongoing Martian colonization would be another one.
A Martian colonization effort is kind of interesting in this regard: because once you send enough people (and ideally, bring enough of them back as well) then 6 degrees of separation starts to take hold if they're distributed within the population. Start building up the quorum of people who've been, have gone, are there now and suddenly that context is leaking back into your general population. People know people who know a returned Martian colonizer. Projects and processes are compared to "this works on Mars, it'll work here" in the same way that everyone on this site who doesn't work at Google probably has said something like "well Google do ...".