Self-orphaning has its value. But all those fictional characters were orphaned, not self-orphaned—they didn’t do the job of separating from their parents by themselves. Is it still good to shed your parents when parents are the ones who bring that about? It seems to very much matter how kids become orphaned. Harry Potter is orphaned in just the right way. His parents love him deeply and lay down memories that stay with him throughout this life. Despite their deaths at the hands of Voldemort, Harry’s archenemy, he carries a sense of himself as wanted and loved. That’s important, according to extensive research in anthropology and psychology, which shows that it’s universally, cross-culturally true that children are damaged when parents don’t give them the sense of being loved.
Most of the fictional orphans are orphaned due to forces beyond the control of their parents, like death, but parents can deliberately leave their children, in both fiction and real life. It happens all the time—especially when it comes to fathers. Barack Obama’s father, for example, left his wife and child in Hawaii when his son was just two years old, first getting a doctorate at Harvard and then moving back to Kenya and on to other wives and other children. Obama talks about living with a painful sense of having been abandoned in his memoir Dreams from My Father. Disappearing altogether is at least better than cutting off children in response to their traits, choices, or viewpoints; there are Christians who reject their atheist kids, Amish people who reject their mainstream kids; parents who disown children for reasons of sexual orientation or gender identity.
In fact, parents can leave simply to find themselves, just as Deresiewicz and Castle would have young adults leave to find themselves. A character who does this, in recent fiction, is Gauri in Jumpha Lahiri’s novel The Lowlands. Dissatisfied with her marriage to a man who was once her brother-in-law, and feeling haunted by ghosts from the past, she suddenly leaves her husband and her ten-year-old daughter in Rhode Island, taking up a position (as a philosophy professor) on the West Coast. There’s no explanation, no communication. Decades pass before there’s any contact. "She had never written to Bela. Never dared reach out, to reassure her.” Deliberately abandoning a ten-year-old, with all the emotional injury that implies, seems completely indefensible. But what about deliberately orphaning an adult child? What if Bela had been thirty instead of ten?
There are better and worse ways to orphan your child, but (come on!) I doubt there’s really any good way to do it. Once you have established yourself as the mother or father of a child, disappearing has many emotional costs for the child, not to mention economic costs. In real life, the abandoned child probably will not get to live in a house called Villa Villekula with a horse on the porch and eat pancakes for every meal, like Pippi Longstocking. Even the abandoned adult child is probably worse off, not better off, outside the pages of fiction, though it’s difficult to find hard evidence on the subject.