There's also the element of datedness to consider. At the time, The Night Gwen Stacy Died was shocking and edgy, but nowadays diminishing returns have taken their toll. You have to say "Amazing Man's girlfriend was murdered and raped and cannibalized and EVIL ALL ALONG" to even raise an eyebrow, so all you end up with is the narm DC has been peddling for the last decade.

Similarly, City On The Edge of Forever was transgressive at the time, but nowadays, Joss Whedon and RTD have flooded the marketplace with relationships that end tragically -- Death by Emmy reel. Uhura/Spock actually going the distance would nowadays be just as shocking as the famous Kirk/Uhura kiss was back in the day.