When people question space they question education, science, economy, glamour, prestige, political and nationalistic advantages, and the entrepreneurial spirit. Space exploration is a package deal with all of the above. It's hard for many people to accept space as significant, but curiosity and exploration are vital to the human spirit and accepting the challenges of going into space is just a part of our human journey. Exploration is what we do because its a natural function of the mind, like an artist who thinks of ideas. This is exactly what Michelangelo Buonarroti would say when people asked him how he thought of his ideas. He told them it was a natural function of the mind, as is curiosity.
For another thing, space exploration should treated with respect because going into space is not easy. There are only a few highly capable people who can do it and go beyond a few moments of wonder at the universe. People involved with space, have unique skills and mental attitudes to brave unknown perils. They are an elite breed of warriors who represent the best that we have on this planet. This is sort of a given in my opinion, so when people question the importance of space exploration, I tend to think it's probably because they don't care. They are only marginally interested at best, and don't think its worth it to go beyond our daily agendas. Part of human nature is that people focus on themselves, and human nature is largely self- absorbed and dictated. Psychologists call this "selfish altruism" which is why some people don't want to invest in anything that doesn't directly benefit themselves. I think its sort of a hypocritical attitude though because cell phones are connected to a satellites and GPS systems which are in fact an invention of space programs.
Also, space is not a quid pro quo. I think its important to understand space exploration is not a case of having a space program or feeding the poor. Those who advance the line of how space is too expensive are not interested in the well being of the poor. In my opinion, that person is just trying to get the votes of the "poor" by convincing the naive that the rocket program is keeping food off their tables somehow. For instance our dropping the space shuttle program did not divert a single dollar to the "poor." All that happened was that a lot of people who worked in the shuttle program lost their jobs.
So the argument that diverting funds or depleting funds, or even removing funds from space exploration programs is ridiculous. Space funds won't solve any of the worlds problems because before space programs, there were still world problems. There will always be world problems with or without space exploration.
Don't forget about a long list of space jobs listed online which pay well - like SpaceX Spacelinks, Spacejobs and Space Careers who all post thousands of jobs which is not taking from the poor, it's supporting families. Jobs are the beginning of a livelihood and these "space" jobs are not just for rocket scientists.
I haven't even gotten to the part about the importance of understanding our planet, our own species and and our relationship to the Universe. Could there be life out there? I think that's something worth knowing.