Superman, and mostly every other hero, has always held a "no kill, more high ground" type of thing even through the death of loved ones: Tim Drake's Dad died for some crazy woman, Spider-man personally killed Gwen Stacy, etc, etc.....These heroes continue on with their no kill thing, not trying to completely shut down villains by, let's say, paralysis or something. They always want the villains to do better or get better someday, but this event just makes Superman weak emotionally as he can't handle this and it seems, through the speech, to even encourage the killing of villains if their crimes are harsh enough.
So Superman, who is as moral high ground as anyone could possibly get, completely breaks down and starts ruling, because of this? This makes his morals seem weak from the very beginning.
Things like game informer or whatever that leaked Bane, Luthor, and so forth, posted the beginning of the Story.
