I am not too sure as to why this was ever removed? Hoping there might be a chance they could be allowed to be attached again - why not have the choice to decide whether to do so or not?
#Make Drones attachable to Planets/Moons again?
stray jetty
slate rampart
Brought it up before, something about them being used to grief ie filling planets with them so you couldn't build, in ef space or something. And it seemed like a general distaste for potential easier base healing