"Just put datacenters in space" might be the very dumbest recurring idea coming from these AI CEOs. It seems to be based entirely on "I dunno, that seems cool."

Solar energy isn't stupendously more available in space than on earth. Even if somehow you get super robots that are able to perform the continuously required maintenance and installation of new equipment, transporting materials into space is very expensive. Venting waste heat in space is incredibly difficult. Dealing with some unexpected situation that requires manual intervention becomes impossible.