Because of the zeroth law. After all, when the settlers start expanding they find no alien inteligent life, but the worlds already terraformed.
Also, Asimov thread.
Maybe that's why spacer society collapsed, because their robots fled their worlds to purge the galaxy.
>>54065274
I assume so yeah
>>54065274
You might enjoy this:
http://sfdebris.com/videos/special/foundation.php
>>54065274
Shines another light on those saintly robots doesn't it ?