I worked for a company that did a lot of DARPA/DoD work, there were plenty of amazingly bright people who spent all of their time making things to make the military better. Sure many were for defense, and often found uses outside of the military. But at the end of the day they all support goals that in the end probably cause a fair amount of more suffering in the world.

So if someone wants to spend their time on something that is completely harmless, and probably brightens a few people's days and may even inspire others to go out and learn something new, I feel that this is a much better way to spend someone's mental energy.