People tend to focus on the most immediate problem, and tend to avoid focusing on that problem until they have no other choice (classic procrastination). As such, people would rather entertain the idea of space-travel and how awesome it would be then actually spend that money on the more immediate problems .... like starving children, our excess population growth, diseases like AIDS, the poor education systems that some areas have, the loose gun laws in America, etc. However, from what I could gather from your post, the 'realist' goes 'No, these are the real issues, not whether or not we can colonise a planet adjacent to our own, but that we are letting millions starve and millions more be oppressed by fundam,entalist regimes'. So what's the issue with a realist? They put attention back on the immediate issues? They have rational priorities? And what does the non-realist have? An adversion to actual problems? So really, the big difference is, the realist complains about issues but very few do anything, while the non-realist completely ignores real issues and does nothing. So far the realist is winning in my eyes.