Someone usually says: “Yeah but what about curing cancer first?!” Guys, the war on cancer(or HIV/Alzheimer’s/whatever) has been going on for decades. We can’t wait forever, as there’s always going to be next disease to take care of.
“And what about eradicating poverty on Earth first?!” Just hear me out... imagine how many people we can put to work(with decent wage!) if we put enough money on the interplanetary flights? We’d invest in science, engineering, production... Well, I’ll keep dreaming.