It is odd how you apparently seem to think you are using the conventional definition of "should" - when you have several people telling you that your use of "should" and "ought" is counter-intuitive.

To be fair, there are several quite distinct ways in which 'should' is typically used. Eliezer's usage is one of them. It is used more or less universally by children and tends to be supplanted or supplemented as people mature with the 'local context' definition you mention and/or the 'best action for agent given his preferences' definition. In Eliezer's case he seems to have instead evolved and philosophically refined the child version. (I hasten to add that I imply only that he matured his moral outlook in other ways than by transitioning usage of those particular words in the most common manner.)