They have problems to solve. It doesn't mean that it's wrong to spend a (relatively) tiny amount of money to give people something to aspire to, and to take pride in accomplishing together. We can do two things at once.
You're only focus on the space program because it's technically similar to food insecurity. But you're ignoring the 50% of the economy which is focused on -- let's be honest -- irrelevant shit. Incredible sums of money (and time and effort) go towards entertainment (hollywood), fashion, jewelry, vacations, and other luxuries.
If you want to divert more resources towards solving world hunger, take it from Hollywood. You don't need to strip bare a source of inspiration that unites people and moves humanity forward.
But, total resources for a Mars colonization effort seems like an order of magnitude more expensive than a simple space program for the benefit of an order of magnitude fewer people. In addition, the capital that is contributing to these efforts (ie Bezos and Musk money) is much more concentrated and can be mobilized in a much more precise manner. I don’t see Mars colonization as a source of inspiration outside of these SV types, and that’s not a significant enough population for me to find this justifiable.
The other is technical (for now) -- hard, but trivial.