That these experiences are not unique to the people experiencing them. I may not want to see all of the ugliness of the human experience but there is an aspect of being able to say "This experience is just not only my own."
Yeah I understand that, and I see the merit in that. But feel you don't have to write about mobsters, drug addicts or Don Draper to get the "human experience".
Case in point; don't laugh now, and don't be fooled by the animated adaption, but the Last Unicorn is, in my opinion, one of the best written and most intelligent books I've ever read (and I read a lot)
It's about unfilled dreams, suffering, aging, greed, disillusionment, the search for "magic" in a world that just doesn't hand it to you. it has layers upon layers of meaning. It intelligently plays with the tropes of high fantasy. That's all the ugliness of human experience but painted in a much nicer colour than "the Sopranos"