It certainly seems a particular feature of Scandi noir. I very much enjoyed the personal interactions of the detective team in The Bridge (and the playful stereotyping of two very different Scandinavian cultures), but it seemed to get more and more about "let's see how many completely implausible and outrageous serial killer incidents we can pile up here just for the yuk factor".
Though the violence porn is not new to our day and age. As George Orwell points out in his essay on the English murder, it was a feature of American inter-war crime writing and there are definite signs of it in Dorothy Sayers. In fact, I think he is spot on about a lot of what he says in that essay: there are reasons when people start wanting to watch graphic violence against women and they are not pleasant ones.
Ruth Rendell is very fond of decaying bodies: I gave up reading her stuff years ago, because it seemed to be focusing more and more on that and less and less on the human interaction side of things.
I enjoyed the early Midsomer murders because they seemed to get so much fun out of sending up the genre and the actors were so obviously having a laugh, but the later ones seem to have lost that sense of playfulness and satire and are just rehashing the same old plots. But at least they don't do body porn.
Lewis does seem to be the only serious crime series that gives dignity to the victim. Oh, and Foyle's War: I like Foyle's War. Quite honest about the racketeering and profiteering that goes on in the war, but very gentle at the same time. And of course the David Suchet Poirot series (some of those stories are so re-written you can hardly call them Agatha Christie). It's the sense that there are values available, values of human dignity and gentleness and uprightness, and that those values are also given a voice and a chance to prevail.
For that reason, I struggled with Luther: fine performance by Idris Elba, but there was nobody there that stood for any values that I would want to see in my own family, friends or colleagues, or indeed that I do see in my family, friends and colleagues. To that extent it does seem very similar to the American thrillers George Orwell was writing about: it seemed to speak for a society that is no longer sure of the rules.