Hogwarts' Castle ... in Florida? Yesterday's news that Universal Studios was planning to open "The Wizarding World of Harry Potter" in 2009 will have prodded the shriek-buttons of millions of young Potterheads, whose relentless campaign for a "really fun holiday this time, Daaad" will have ratcheted forward a few more irreversible notches.

But for those parents who, through sheer diligence, have found themselves immersed in J K Rowling's world - fielding debates like "what is the seventh horcrux?" or "is Snape really evil?" with casual ease - this news clangs badly, like Quidditch armour dropped on a flagstone floor.

The initial plans show a dark, cloudy, white-capped scene. If you've ever toiled and broiled your way round a high-season Florida theme-park - where the dominant sensation is of being positioned 20 miles closer to the sun than seems strictly necessary - you'll wonder how they'll get the plastic snow to stay un-melted.

But the next reaction is more aesthetic. Harry Potter - damp, cobwebby, sepulchral Harry Potter - in the land of the George Foreman Grill and the fluorescent fanny-pack? As the Potterheads might write on their fanfiction pages: Just. Not. Right.

The JK Rowling who initially resisted filming the books because she feared that Harry would be too "Americanised" has clearly softened her stance on that particular assimilation. The new theme park will be part of the Islands of Adventure area, right next to Marvel Comics Land and Spielberg's Jurassic Park.

To give the writer her due, Rowling's quality control over the various exploitations of her creation has been pretty fastidious. And as you watch your 10-year-old getting completely lost in a well-written 700-page book, steadily answering her vocabulary questions about what "mortal peril" or "scrutinised" means, you can imagine vast capitalist franchises based on much less worthy foundations.

But I am here to complain, in a slightly peeved manner, about one aspect of the location of PotterWorld: that nobody ever seems to have thought, including Rowling, that it could have been based in Scotland. The only other mooted location I've been able to find, proposed by Disney in 2004, was Singapore. And let's take for granted, in terms of the sensibility behind the books, that the Scottish climate might be a bit more appropriate than Orlando. Artistically, though there are many elements swirling around in the Harry Potter mythos, surely the Caledonian theme is the strongest.

The Hogwarts Express may be leaving from King's Cross, but it hurtles northwards and greenwards, where it eventually arrives at a scene which Walter Scott and R L Stevenson laid the template for - a looming mist-wreathed castle on a mysterious loch. Hogwarts also touches on what Tom Nairn once called "Balmorality": this is an isolated boarding school, surrounded by dark forests full of huntable creatures, and a stamping ground for half-blood princes.

Though Rowling didn't get Sean Connery as her first choice for Professor Dumbledore, she did get Robbie Coltrane as Hagrid and Maggie Smith as Professor McGonagall. And how much more Calvinist and Presbyterian a hero do you get than Harry Potter - literally marked on his head with the stain of evil, perpetually struggling with his own sense of being unworthy of his status?

There's no doubt the Potter sensibility, and particularly the edifice of Hogwarts, is pre-dominantly Scottish. But I want to gently suggest that not only could the theme park have been built in Scotland, maybe it should have been too. The burden of responsibility falls very lightly on Rowling, and more heavily on the deficit of strategic power in Scottish politics and society.

The Bristolian Rowling is about as naturalised an adoptive Scot as you could imagine - married to a Scottish-born anaesthetist, Neil Murray, both living and working in Edinburgh and Perth, her children educated at local state schools, with Gordon Brown a family friend. It's also well known that the very genesis of the Potter books couldn't have happened without two kinds of benefit from the state in Scotland - unemployment benefit as a single mother, and a grant of £8000 from the Scottish Arts Council to help her stabilise her finances and complete the first book, The Chamber of Secrets.

Bring the fiction and the biography together, and you can see why Rowling might have considered that her great return gift to Scotland - as one of the enabling conditions for her mighty empire - would be a global-standard tourist attraction, based on some aspect of the Potter mythology.

The bigger problem by far is that, over the last decade of mounting Potter-mania, there has been no executive power in Scotland strong enough, or imaginative enough, to give Rowling a clear option to base such a theme park in its natural home. That weakness might be beginning to change, with the end of Labour rule in Scotland this May and the arrival of an SNP government. But it seems to me quite an indictment of the Scottish tourism industry (with its own resplendent quango Visit Scotland) that the possibility, to my hearing, has never even been raised - particularly given the steady drone about tourism being our "biggest industry of the future".

Anyone familiar with the Scottish landscape, watching the movie's tracking shots around a simulated Hogwarts' castle, could easily identify possible locations. And it's not that we can't build extraordinary and world-class new edifices: take the Scottish Parliament building, followed soon by Zaha Hadid's Transport Museum in Glasgow (though hopefully we'd have learned enough about managing costs from the former).

The cachet of the world's biggest arts festival in Edinburgh - whose literary credentials, with the book festival and the Unesco's award of first ever "City of Literature", are unparalleled - might have provided a less crass, more resonant overlay to the project.

Meaning as much storytelling, creativity and drama, as robotic postal owls and first-person-shooter wand action. The technological challenges would have to be just as enthusiastically met, however: I know I wouldn't get my daughter through its gates if there weren't at least one near-authentic Quidditch ride in the building. And a properly animated Death Eater that frightened her right out of her Converses.

All in all, though, I suspect that Scotland has missed the coracle here - not enough sovereignty, and vision, and maybe capability, at the crucial moment. In any case, it looks like all remaining Scottish ingenuity is going to be steered in the direction of clean coal capture, wave machines and wind farms. Ah well.

Personally, I will resist the propaganda to haul myself to the state of the hanging chad, and strap on my Quidditch roller-coaster harness and eat melting Bertie Botts' Every Flavor (sic) Beans, until the very last minute. And even then, I will probably travel under the command of the Snape Army. That is: moodily.