WERE he still alive, my grandfather would have been unimpressed by last week's announcement that the Turner Prize for 2015 is to be presented at the old Coplawhill tram depot in Glasgow.

He began his career as a tram conductor and ended it as director of publicity for the corporation, a role in which he turned out hundreds of posters, timetable covers and other visual material. In those impossibly distant days, those tasks involved such antiquated skills as lettering and being able to draw, the absence of which is no impediment to – indeed, is positively a requirement for – Turner prize success.

Of course, when he went there, Glasgow School of Art went in for that sort of stuff. In recent years, it has turned out almost 30% of the nominees for the Turner Prize. Not all of us regard that as progress.

The Turner Prize, and for that matter much of the contemporary art world (and in particular publicly-funded parts of it), is not content to challenge the historical understanding and practice of art, as 20th-century modernism did. On the evidence of the nominees and winners over the past couple of decades, it appears actually to hate any elevated notion of art at all.

These are the sort of people who hate traditional sculptures, but might regard the act of tearing down a sculpture as an important piece of performance art. (They're very keen on labelling things as "important", probably because, since the work so patently isn't, their own importance can only be maintained by denying objective reality.)

Small wonder, then, that they should seize on Glasgow as a particularly suitable spot. A city council hell-bent on ridding George Square of first-rate statuary in favour of an open space more convenient for the Proclaimers to deafen drunken morons at Hogmanay is clearly in tune with the Turner's aesthetics. Like the barbaric proposals to remodel the centre of Aberdeen, there seems to be very little justification for this vandalism, other than giving councillors yet another excuse for spending public money on something for which there is no public demand. If they want to stage pop concerts, they have no shortage of venues, including that big shed down by the river. If they must have them outside, they could always try one of the parks with which Glasgow is so abundantly supplied.

The increased emphasis on the artistic revitalisation of Glasgow since it became European Capital of Culture in 1990 is stated so regularly that some people actually believe it to be universally self-evident. The truth is much more mixed. Of course there have been many improvements – the renovation of the Kelvingrove, one of the UK's greatest museums, is terrific. The Tron has just put on the best pantomime I've seen. Scottish Opera clings on, and The Burrell Collection celebrates its 30th anniversary this year.

But it should not be forgotten that during the same period, the council has put up some shockingly bad public art, allowed some horrific new buildings and neglected, or attempted to demolish, some of the city's finest structures. Until very recently, there seemed to be a positive vendetta against Alexander "Greek" Thomson, perhaps our greatest architect, even while there was great enthusiasm for driving motorways through the heart of the city and sticking up monstrosities like Lord Foster's woodlouse. A city in which the BBC can spend £350,000 of public money on Toby Paterson's washing line of coloured panels in front of its offices at Pacific Quay, to general approval, while Greek Thomson's Egyptian Halls remain under threat of demolition, doesn't take culture seriously.

It's no surprise that both the city and the contemporary art establishment try to ignore traditionalists such as the neoclassical sculptor Alexander Stoddart, who has protested at the plans to remove the square's statuary, and who must be a leading candidate for the title "least likely ever to have featured on the Turner shortlist". But even doing anything as traditional as, say, figurative painting is also suspect: people like Peter Howson, Jenny Saville or Ken Currie have never been nominated, either.

Too much of the "culture" on which Glasgow now congratulates itself is, like the standard Turner fare, not merely utterly pathetic in comparison with, but pre-emptively designed to denigrate the achievements of the past. It is not a clash or a challenge, as modernism was to traditionalist forms, but a refusal to accept any notion of value at all. Modernism may have been difficult and obscure, but it was not meaningless – in Clement Greenberg's famous formulation, it offered the choice between the avant-garde and kitsch, arguing that the former was all that could provide meaning in a world stripped of the former certainties offered by religion, hierarchy and tradition. Compare that with Damien Hirst (in his 1995 Turner Prize speech): "It's amazing what you can do with an E in A-level art, a chainsaw and a twisted imagination."

Conceptual art began with Duchamp's urinal, and should have stopped at the same moment. That one piece said everything which needed to be said about it, and everything which could be said by it. The critic and artist Matthew Collings, who initially admired, advocated (and produced) this kind of work, put it best when he admitted that Turner Prize art was something superficially shocking which is meant to express some banal idea or other. "The ideas are never important or even really ideas, more notions, like the notions in advertising. Nobody pursues them, because there's nothing there to pursue- today's art is a kind of hell."

When Glasgow became European Capital of Culture, it was greeted by the ignorant elsewhere in Britain with some surprise. For Glaswegians, it ought to have served as a reminder of the colossal artistic inheritance which we already had. Unfortunately, rather than celebrating and building on the achievements of figures such as Thomson and Mackintosh, or the Glasgow School of painters, too much attention was devoted to embracing the tawdry, gimcrack culture of post-modernism.

This ideology, and the art which exemplifies it, not only fails to bring any meaning to our lives or the world around us, but denies that any such meaning is possible. High culture is difficult, you see. Because great works of art have meaning, they need us to work to understand them. It's easier to claim that Mark Wallinger wandering around in a bear suit is much the same thing as The Night Watch. Because if nothing has any meaning, you're free to concentrate on the novel, the tawdry, and the sham, and ignore the real value which has been around you all the time.