The Dark Age/Iron Age is really coming to an end.
During the Dark Age/ Iron Age, EVERYTHING and EVERYONE was dark and evil with no difference between heroes and villians, even Superman was murdering defendless foes. Batman was a jerk, Hal become a serial Killer, etc.
During this New Age it seems that the Heroes will start acting like real heroes, but the villains will still be dark and evil and do gross and sicking acts.
As long as ONLY the Villains are acting like jerks and are the only ones doing the murdering, I guess it's an improvement, but Heroes if they are real heroes should never act that way, like they did during the Dark Age/Iron Age.
I don't have a problem with jerk heroes or characters that behave badly - in fact, the Shannon Doherty-esque scheming man-chaser Mantis, and the snotty Leona Helmsley-esque Moondragon are both two of my favorite characters not in spite of, but BECAUSE of their many flaws as people (that, and the fact they had Steve Englehart, arguably the greatest comic book writer that ever lived, characterizing them).
But you are right when you say that villains should be the people that primarily make mischief and heroes should be kept behaving heroically, not because this has a value in and of itself but because that is how they are characterized as being and to write them otherwise would be bad writing.
A lot of people started complaining when Geoff Johns had Gorilla Grodd eat human flesh, but I don't have a problem with this. First, Grodd is a savage, fearsome gorilla, and making him carnivorous is in the Edgar Rice Burroughs pulp tradition. Second, Grodd has been characterized as an amoral rattlesnake ALREADY; the idea that he would eat people isn't exactly the most shocking thing in the world. Destroying the Earth with a mind-suck ray powered by the sword Excalibur is actually a STEP UP from just eating people.
It's a step in the right direction if the DCU is going with "LAW AND ORDER syndrome." Watch the show, you notice that only the bad guys smoke; good guys do not. I feel very sorry for Michael Madsen on the SVU set when he starts to have a nic fit.
The Stupid Death of Conner Kent didn't make him any more heroic to me; he still seems like a pretty flat character. They ruined him when they gave him that stupid T-shirt, gave him names like "Conner Kent" and "Kon-El", and made him Superman and Lex Luthor's baby. He was more interesting as simply a hormone-driven teenager with an ambiguous origin.
I disagree. I thought Conner's end was poignantly written and heroic, especially in light of the fact that Geoff Johns did everything he could to make the character likeable. Geoff Johns does this: make characters likeable and then kill them off shortly after. Superboy's death was something that Supergirl's death (which left me slightly nauseous) failed to do: create a heroic sequence and not have the character die like a dog.
The YOUNG JUSTICE period, where Superboy and his moron buddies were presented as pizza-eating slackers (with Superboy with an origin so labyrinthine it bordered on the mythological) was the absolute nadir of DC Comics in the 1990s, featuring irritating stereotypes of how old guys think kids talk and act. It was like a Bizarro World ENDER'S GAME: Orson Scott Card showed that kids are far, far smarter than adults give them credit for, whereas YOUNG JUSTICE showed them as far, far dumber.
It really says something that Johns was able to get an old school guy like me to like Superboy by having him achieve maturity.