It was more than a little disheartening to read children's author GP Taylor railing recently against the advent of the celebrity children's novelist.

According to Taylor - whose dark and downright scary novels show that ex-vicars are not all made of sugar and spice - "thousands" of good children's writers are being squeezed out of the market by big names with huge budgets behind them. "It's all about marketing campaigns and getting on the couch on a television show," he said, dismissing these titles as "the literary equivalent of lift music", a frankness that may explain why he's no longer a man of the cloth.

The bestselling Yorkshire writer, whose earlier credits include being a policeman and exorcist, says he too is being marginalised. In fact, he's already quit the children's book world. "I don't stand a cat in hell's chance of getting published anymore. I have three big films coming out and no children's publishing deal. How weird is that?"

Taylor's gripes were made public just a few days after I had been reflecting on the astonishingly high quality of children's books today. The trigger was the arrival of James Robertson's translation into Scots of Julia Donaldson's The Gruffalo's Child. The Gruffalo's Wean (B&W, £6.99) is the follow-up to the much loved The Gruffalo in Scots - "A moose took a dauner through the deep, mirk widd. A tod saw the moose and the moose looked guid..." - and it too starts with murky fears that send a pleasing shiver up the spine.

Compare those lines with these from Katie Price's first pony tale for little girls, in which Jess has had her first riding lesson and realises her world has been "turned upside down". She now adores all sorts of ponies: "Small ones, fat ones, naughty ones, nervy ones, even cheeky ponies - they were all brilliant! Jess knew her mum would never be able to buy her a pony of her own, not unless she won the lottery!" I stopped there, so I can't tell you what happens next, and I doubt Katie can either, since she admits these books are ghostwritten.

Not all celebrities are terrible writers, though. David Walliams's droll and feeling stories for eight to 12-year-olds buck the trend, as do Julianne Moore's Freckleface Strawberry tales, but this pair are, unfortunately, rare. As a rule, the likes of Frank Lampard (yes, the footballer), John Travolta, Madonna and other literary interlopers think adding a children's novel to their CV is an easy way to broaden their portfolio. It is, you could say, sickening. Children's books are the gateway to literature, and to think that this most important of all libraries is a fairground where anyone can get on the rides regardless of talent is not only deeply insulting to good children's writers, but potentially damaging to children.

Publishers who take on such projects simply for profit ought to be ashamed. Is this what they came into children's publishing for? Quite apart from the youngsters who are being shortchanged, what about the adults who cough up for something not even fit for Hammie the text-messaging Hamster's litter?

If these parvenues can treat kids' fiction like the icing on their careers, it's no wonder ordinary folk think writing children's books is like baking cup cakes. I've lost count of the number of times someone who's never written anything longer than a birthday card has told me they are going to write a kid's book. They seem to think it's the first rung on the literary ladder, the Playdough version of the real thing, which anyone can take a stab at.

I used to try to look interested, as storylines were outlined at length. Now, I stop them in their tracks. Why pander to the very same ignorance and unfounded self-belief that leads footballers and film stars down the same path? We can only be thankful that most of the red-carpet writers are about as durable as breadcrumbs in a fairytale forest. But as even Handsel and Gretel should have known, you really should leave the woods the way you find them.