I'm a big supporter of the space program, with an emphasis on robotic exploration but with a gradual development of manned space capabilities. I think this 2024 deadline is capricious, but by no means arbitrary (think: election year). The resources needing to be diverted for this are huge, and the incremental risk by pushing this so far, so quickly make no sense in today's economy.
Think of the science we could do with the $$$ it would take to send a man to the moon. Fleets of small robotic explorers, development of all kinds of tech, but instead it would get funneled into keeping meat alive.
Again, I'd love to see further moon landings before I die (I'm 51), but rushing things makes no sense at all. It's a political stunt, plain and simple.