Maybe it’s a question of degree - I didn’t watch all of DS9 and don’t remember those two episodes, but I honestly can’t think of other instances where characters walked around bemoaning the state of affairs beyond a comment or two. In the Harlan Ellison episode with Edith Keeler nobody commented on it being a shame that there were still millionaires while poor people were eating soup kitchens, for example. Same for the Gary Seven episode - there were brief matter of fact comments on young people being unhappy with things, but no lecturing on the military industrial complex profiting off the Vietnam War. Maybe what you’re talking about evolved later.