This is a good soundbyte, but misses that the world overall is getting richer and safer every year. The UK is not getting poorer. The US is not either. There's always going to be someone, somewhere who falls through the cracks. That doesn't mean we need to stop humans from exploring the solar system until everyone, everywhere is covered.
If you really care about solving homelessness and income inequality everywhere, why not take it from the truly "useless" industries like entertainment, cosmetics, toys, or luxury cars? Rather than the one industry trying to build a long-term future for humanity.
The US spends $50B a year on pet food or whatever. Get rid of the pets and take that money if you want. I don't see why you are offended that a couple billion is being spent on something that actually matters.