I have seen many people on HN and elsewhere use the same argument in other contexts. For example, to justify spending on the Apollo program on the grounds that

I have seen many people on HN and elsewhere use the same argument in other contexts. For example, to justify spending on the Apollo program on the grounds that some of the money was used to fund research which turned out to be useful outside of manned space flight. So apparently it is indeed considered a perfectly fine state of affairs. I'm being a bit facetious of course, I just find it funny that people's acceptance of this argument depends on how much they support the primary subject of the funding.