Terence Blacker: What's the point of getting divorced if nobody's going to get the blame for it?

Romance has had a pretty good run until recently in the stories of the famous that provide the light relief in our daily news. There were all those lavish weddings of mini-celebrities in Hello! and OK!. Entire magazines are devoted to who was seeing, or not seeing, whom.

Parenthood has done well, too. Ever since Demi Moore was photographed, naked and pregnant, for Vanity Fair, actresses have liked to pose with their bumps for magazines. Rights to exclusive first-baby pictures are regularly auctioned to the highest bidder. No celebrity interview is complete without a few endearing insights into the famous one's family life. Children are photographed with their high-profile parents, arriving at airports or attending sporting events.

Now it is the turn of divorce. It is no longer enough for marriage break-ups to be reported from the outside. Increasingly the soon-to-be-unmarried are inviting their public to share their pain. The end of a marriage has become another little psychodrama of self-promotion in which a celebrity can reveal his or her vulnerability and sensitivity.

Katie Price, a trendsetter when it comes to the commodification of private life, has managed to keep herself in the limelight for the past few years with a series of well-publicised break-ups. This month, the singer Katy Perry has gone further, allowing cameras for Part of Me, a documentary about her, to catch the moments when her recent, brief marriage to the comedian Russell Brand began to unravel.

Her motives, of course, were entirely selfless. "It's not about the problem; it's about how you solve it and, if I can be an example, showing people how they don't have to lay down and die because they've been thrown a curveball, that's great," she has said. It was "not nice to air all your dirty laundry because it stinks… but I couldn't avoid the elephant in the room. The truth will always prevail".

We can expect more dirty laundry in the coming months. In other divorce news, Tom Cruise and Katie Holmes have been accusing one another of "playing the media". Me and my divorce: it's the next big thing.

The problem is not with the famous – those living in a celebrity bubble tend to have lost contact with normal human behaviour some time ago – but with the wider effect of divorce as entertainment.

Anyone who has been through the end of a marriage will know that the process brings its own peculiar miseries. It is not just shatteringly disappointing when commitment and love (or what seemed to be love) go wrong; it is a massive personal failure. If there are children involved, there will also be – or should be – a powerful element of guilt.

Yet Perry's elephant in the room has nothing to do with herself. In her reality show, the prevailing truth propagates the convenient illusion that the failure of your marriage is never really your own fault. It is merely life throwing you a curveball.

The fact is, guilt and shame have their place in a divorce. They show that something important has been lost. If there is no sense of failure at that point, then what was the point of the fuss, solemnity and ceremony that came before? Even in the rare cases when a husband or wife is clearly the sinner, the other at least bears the responsibility of having made a bad choice, of having loved unwisely.

Perhaps it was inevitable that, in an age hooked on emotion and drama, the various agonies of divorce would eventually become the stuff of self-promoting entertainment. The material is all there: the personal pain, the aching late-night conversations, the startling confessions, the silences, the bewildered, miserable children, the division and loss (sometimes for ever) of friends, the ghastly money wrangles, the cynical manipulations of lawyers, and sometimes, at the end of it all, the drama of little lives being played out in a family court.

After it is all over, the grim process can energise the creatively minded. A vast library could be created of brilliant, sour, funny divorce novels, films and songs. John Cleese built a whole stand-up show around his contempt for his ex-wife. The memory of divorce lives on, no matter what happened after it. "It's the lurking fact, a slice of anger in the pie of your brain," as that expert in the subject, Nora Ephron, put it. "People say you forget the pain. It's a cliché of childbirth, too. I don't happen to agree. I do remember the pain. What you really forget is love."

The new celebrification of divorce is different from these fictions and bitter memories. It is live, and in the present. The exposure of twists and turns in the drama, of tears shed and words spoken, simultaneously trivialises what is happening and makes it worse. The self-generated publicity around the breakdown of a famous marriage is as harmful as the effect of gossip and backbiting on a civilian one. The more personal pain becomes public property, the less likely it is that anything good or positive will be salvaged from it. Divorce should be as private as can be managed.

Of course a marriage, once it has gone irretrievably wrong, should end. Freedom from it, particularly for a woman, can be a moment of exhilaration and renewal. But when the famous turn those moments into self-serving, emotion-drenched media fodder, it sets a ruinous example to those in civilian life whose marriages are on the rocks.

Russell Brand, who must be viewing the antics of his ex-wife Katy Perry with some alarm, has also begun to play the role of divorce role model. In a TV interview last week, he said, "It did work out in a way because you are married for some time, and that's really good, and then you're not married, and that's really good too. You just have to have acceptance of things."

Alternatively, none of it is really good. When divorce becomes little more than another little show, a sad little episode with no morality or personal responsibility, then marriage becomes meaningless, too.