Random Fermi Paradox solution of the day:
Nobody goes into space and colonizes the galaxy because only Moon Nazis want to do that, and after experiencing a few dozen genocides all sapient species learn the safest thing to do when you see a Moon Nazi is to murder them immediately, it's the only way to avoid the genocides.
This is how I learn that not only did someone make a movie about Nazis living on the moon, they even made a sequel.