Something like the Australian celebrity phenomena happens when people start talking about NASA spinoffs, here's how it works: a speaker creates the implication that civil servant NASA scientists developed some new technology which was subsequently "spun off" to form a commercial product. The most common example of this is Velcro, but there are plenty of others. Whenever you dig into these claims you almost always discover that the entirety of NASA's contribution was in the form of a check. Some people don't even see the deceit in this, suggesting that any NASA funded research is NASA research and therefore any commercial products that result are spinoffs. I've always wondered how the scientists and engineers who do the work to create these products feel about that.
It is an obvious truism that no human-made object could have been placed into space had it not been for the space program of one nation or another. Oh wait, no, that's not a truism at all is it? The first rocket to leave the Earth's atmosphere was a German V2 rocket in 1944, long before anyone had a "space program". Despite this, it seems a lot of well meaning people want to perpetuate the myth that everything in space is a result of the space program.. and a lot of things on Earth too. Watch this short video for my least favorite demonstration:
It disappoints when a speaker says something like this.. it fills you with inspiration for about five seconds, only to have the nagging rational part of your brain chime in with: umm, excuse me? That's not actually true, ya know. I think kids who are inspired by such speakers to follow their dreams will feel terrible betrayal when they eventually discover they've been lied to.
Before anyone accuses me of Tyson bashing, let me say that I'm otherwise a fan of his work and encourage everyone to watch the full 2.5 hour talk. Maybe he doesn't know that NASA didn't invent cordless power drills and their contribution to LASIK eye surgery amounted to writing a check long after it was invented, and maybe he's unaware of the history of the global positioning system and that "space exploration" had nothing to do with it. I don't know, but considering how awesome he is, I find that extremely hard to believe.
But let's take this argument where no-one seems to be willing to go.
We all love the global positioning system - you might say it is the pinnacle of human achievement - surely we should support any program of government spending that can result in fantastic technological marvels becoming such an everyday part of our lives, right? If you don't necessarily agree with that, then perhaps it is because you know the primary justification for building and launching the GPS satellite constellation was global thermonuclear war.
In fact, the development of satellites in general and giant space telescopes in particular, was the cold war need to spy on the Soviet Union. Love the Hubble space telescope? Well then, you should support more government spending on the military industrial complex. Actually, you should long for the days when school children practiced hiding under their desks with visions of nuclear annihilation dancing in their heads. With the Soviet Union gone we'll have to find another enemy but that shouldn't be too hard.
Or - just maybe - you might think that regardless of the spinoffs and the side benefits, it was still bad to have forty years where two great superpowers teetered on the edge of oblivion staring at each other across the void and hoping neither would be so stupid as to make the first move in a game neither side could win.
Similarly, the space program cannot be justified by spinoffs and side benefits. It can't be justified by how many kids are inspired to become scientists and engineers instead of lawyers and doctors - no wait, politicians, yeah that's better. In order to convince your fellow taxpayers that human spaceflight is in the national interest you have to say what it is for and why that is a good thing. We can disagree on what that is, but the last thing we should do is give up and list the side benefits as the actual purpose.. and stop lying to the kids ;)