At least for India there's very little argument to be made other than the fact that space exploration and building space technologies is a net benefit to the country. Even in strict financial terms it's beneficial.

However, it's also worth pointing out that when the US went to the Moon with the Apollo program it had extensive racial and sectarian strife, it had extreme poverty, and it was still a developing country. Something like 1 in 5 US households did not have complete indoor plumbing, and many did not have electricity. The argument that one must have everything "at home" completely sorted out before reaching the stars is one that can quite easily be turned against the history of US space exploration.