For those who've seen no news, Elton John and David Furnish, with the help of an anonymous Californian surrogate and a separate egg donor, had a baby boy, and called him Zachary Jackson Levon Furnish-John. According to the Mail, this means the baby has two mothers and two fathers. Though since they put father in inverted commas, I think that means each one is only partially a father, and they add back up to one. The technicalities of prejudice are like the laws of cricket. You can get someone to explain, but you'll immediately forget.

Imagine it: they call you Rocket Man, and not (always) as a joke. You are worth £185m, which – for those who find it hard to conceive of large amounts – is enough to fill the house with 20 grands' worth of flowers every week, every month or every year (if only urban myth would be more precise!). You are Liz Hurley's best friend. Where are you going to go from there, but to impregnate a virgin (let's say she was a virgin) and have a baby boy on Christmas Day? Oh Elton John (and David Furnish)! Congratulations seem inadequate, and also Baby Spice (one of your many Spice confidantes) has already proffered them on Twitter. Someone really ought to be naming a religion after you.

There are sound reasons to think they'll be very good parents. Furnish said once that going out with John was like dating Father Christmas, all you had to do was express the slightest interest in any hobby at all, and its entire apparatus would appear at the end of your bed the next morning. Golf, llama farming, the violin, no problemo (it's true that this could result in a spoilt child). John has recently retired, and Furnish took early retirement from the world of work in 1994, to concentrate on the world of love.

In these soi-disant child-centric times, this could be the new parental ideal, a household in which the parents have no obligations at all, except to be extremely fun and educational, all day long. "We don't want to put the raising of children into the hands of nannies and housekeepers. We want to be active parents," John said some months ago, at the time apropos nothing, but in hindsight apropos a freakin' real life baby.

Nonetheless, John is 62, all the newspapers report, and Furnish is 48, they add, just in case you think he's some spring chicken who will live for ever. Just the mention of the facts raises the spectre of how much disapproval older-parenthood arouses.

These are the arguments against the older father: if the mother was that old, people would condemn it, ergo we have to condemn men in the interests of equity. That's obnoxious; a true feminist takes no enjoyment from making sure everybody gets as much hassle as a hypothetical woman would. The main rhetorical point is that they will be too old to play football. I think football is meant as synecdoche for all physical activity, but the argument is still frankly weird: if someone who was disabled had a child, nobody would say they were depriving their offspring of ball sports.

The more macabre, sonorous point is that you might die before your child graduates. I like the sly undertone, "I'm intelligent, you're intelligent, we're all graduates here … so haven't you got it in your pea brain to think about graduations of the future?" But it's unfair – a person with a family history of not living very long would never be hit with the charge of selfishness if they chose to breed within 20 years of their expiry date. And graduation, by the way, is exquisitely boring. It might be the least eventful thing that can ever happen within the parent-child dyad.

Of course, the real objection isn't to the age of the parent, indeed, it has nothing to do with parents or children. Rather, it's a reaction against the audacity of choice.

You can misspend your youth on frivolity (vexingly for the frivolous, this can mean anything from drugs, drink and music, to an interest in interiors and fancy dress parties). You can have an "alternative lifestyle" (this actually means gay, though in some circles, women who pursue work that they enjoy are considered dangerously alternative). Most people accept that it's no longer on the cards to put you in prison, but at the very least, all this should come at the expense of respectable pleasures, like breeding.

This is made engagingly clear in the Daily Mail's coverage, which segues from John's age to his erstwhile drug addiction, to a picture of the couple in fancy dress, as if these features were co-terminous, belonging to and defining the territory of childlessness.

What's amazing is that the people who do deride the Furnish-Johns on the basis of age and lifestyle, the people who are wondering whether this baby is an "accessory" (because they're gay, and gays are only interested in handbags) are so outnumbered by those who don't. Almost nobody in the mainstream is decrying Elton John's age, because without a subtext in which we all disapprove of his lifestyle, it wouldn't make sense. It has no engine, it would sound vindictive. So even the hoariest old traditionalists rejoice at the tidings. Homophobia might not be dead, but we're seeing the final twitches of its rodent bones; it's slowly turning into one of those things only children do. It's quite a moment. And on Christmas Day!