I'm sure this is not a popular opinion here, but as long as I trip over homeless people, sleeping on the sidewalks, on my stroll to work, it's weird that space exploration would pop up as a "must" instead of a "nice to have".
So, why not do both, and prioritize the money accordingly?
Who knows what the next stages will bring? if we mine platinum and gold-heavy asteroids, we can make common use of previously-rare elements, or (as Bezos wants) foster an environment for heavy-polluting, but critical industry, to go off-world.
Never mind that the entire technological evolution necessitated by the process can be used to better humankind's lot.