Richard Stallman and GPL discussions certainly do mention ethics as part of the considerations. I agree that no person is completely disjoint from ethical considerations, with intelligence. But as this thread explores, there are multiple points of view, unclear and untested aspects legally within multiple legal jurisdictions.
But you make a large leap when you say "they should not mention" .. It is a dramatic statement, not a logical one, it is more in common with persuasive, political speech than logic there.
As noted by others, a useful simplification is to focus on one particular LICENSE at a time. Is this license ... x y z. As Google did long ago and as Github started to do and as the OSI does and as FSF does... like that.. not debate on the entire concept, but instead focus on the implementation, as software does.
