IT is not the first time an author has leapt to the defence of his native city, but Alexander McCall Smith’s plea for preserving Edinburgh’s charms must surely rate as one of the most comprehensive writerly denunciations of a municipal council. In an online article, McCall Smith, one of whose recent books is a paean to the aesthetic delights of the capital, calls on the city’s panjandrums to improve its planning and tourist regulations, or risk being swamped by tat.

Asking for hotels to be built on the periphery, Airbnb leases to be more tightly controlled, and for ordinary people to be enabled to live as a community in the old town, Smith fulminates at the denigration of his beloved home.

Who can blame him? At this time of year especially, Edinburgh’s decline into seediness and vulgar bling is plain for all to see. Once likened with awe to Athens, now it is the Blackpool of the North.

Forget architecture and culture as a lure, these days you are never more than 10 feet away from a cocktail or burger. A few years ago, citizens were thrilled by white fairy lights in the trees beneath the castle, which added a frosting of glitz to their regal surroundings.

Since then they have been overshadowed by the flashing neon of fairground shows, which whirl over pedestrians’ heads like fluorescent dervishes. This year, an 80-foot Drop Tower has been built in George Street, which can be seen not just from all parts of the New Town, but also the moon. Perhaps intended as a warning to low-flying pilots, it announces that Edinburgh, once the most enviably elegant and sophisticated of locations, is vying for Las Vegas’ crown.

The tower is only the most recent gimmick aimed at drawing crowds and their loot, a series of initiatives locally known as TackFest. Indeed, who needs the crowds? If they could send their cash by PayPal one suspects the leaders of the city’s marketing department would be just as happy. Because money, needless to say, is the driving force behind almost all the new developments, be it ugly hotels or buy-to-let flats, that are sucking the life from a place that was once a by-word for taste.

There was a flicker of hope, when the Old Royal High School was saved from being turned into an Aztec-style hotel. But that is the only good news story in a long time. Since then, more residents have moved out, or sold up. When a friend in the Royal Mile heard that I had relocated to the Borders, his expression was of a shipwrecked sailor watching from the listing deck as his mates scull off in the last lifeboat.

Speak out against the marketeers’ wheezes and you will be called a killjoy. Those who care about Edinburgh, however — who are genuinely sorrowful and upset, and utterly helpless in the face of its diminishment — know the real culprits. They are the apparatchiks and opportunists who, steadily and heedlessly, are killing what made Edinburgh such a joy in the first place. And they seem impervious to the mayhem they are causing. Asked, for instance, for his response to McCall Smith’s comments, the chair of Marketing Edinburgh, said that “our strategy has to be for the Edinburgh of the future — not the past.”

He could not be more wrong. The reason people have always come to Edinburgh is to see and feel and taste the past, to walk its murky, damp closes, and cobbled courtyards, and see a pristine classical skyline that reaches out towards the Firth of Forth, like a painting of paradise. Those in search of the future go to Beijing, Mumbai or Sao Paulo. Edinburgh’s raison d’être is the history from which it is made. Why else would the world’s finest and biggest arts festival still flourish here? But if what makes the capital so alluring has lost — and already its glister is fading — its hold on such events will loosen. Once gone, and the income it raises, it will take a lifetime and more to win back.

The capital has always been one of the most mysterious, fascinating cities in Europe. Famed for its sternness and formality, for its chilly smiles and snell winds, it made its name as a magnificent contradiction. Nowhere else did rich and poor rub shoulders quite like this, nor squalor and opulence, rectitude and debauchery, genius and criminal depravity.

In the quintessentially Edinburgh novel, Muriel Spark’s The Prime of Jean Brodie, the heroine takes her pupils for a brisk walk when the school’s central heating breaks down. Leading her crocodile across the leafy Meadows, into the slums of the Grassmarket and down the Royal Mile, Miss Brodie spouts lessons as she goes. In those days — the early 1930s — these were dreich, impoverished districts, but they were rich in atmosphere and history. Would she recognise it all today? Yes, but she would have to look hard. Where Miss Brodie could show her charges the capital’s bare face, now it is all but hidden beneath banners and bars, eateries and market stalls, street furniture, pounding music, graffiti, litter, and lights so bright they blind you.

Worst of all, it is becoming an empty shell. As locals retreat to the suburbs, where they can sleep in peace, and step outside in the morning without tangoing around ticket touts and guided tours, the spirit of the living, breathing city is evaporating. McCall Smith could not be more correct in pinpointing this as an urgent malaise.

Even more than the despoliation of the New Town, the erosion of normal life in the Old is tourism’s biggest casualty and crime. Unless measures are taken to remedy the cost of living in the centre — cost in the widest sense — the Royal Mile and its environs will turn into another Venice: an empty stage-set for passers-by, a performance space rather than a real place with a vital, beating heart. That’s not what I call a city.