Charles Saatchi, the most important British art collector of his generation, has launched an incendiary attack on the buyers, dealers and curators who populate the contemporary art world and concluded that many of them have little feeling for art and cannot tell a good artist from a bad one.

Writing in today's Guardian, Saatchi paints a scathing picture of the contemporary art world and says that being a buyer these days "is comprehensively and indisputably vulgar".

He says: "It is the sport of the Eurotrashy, hedgefundy, Hamptonites; of trendy oligarchs and oiligarchs; and of art dealers with masturbatory levels of self-regard." Saatchi described the Venice Biennale, scene of the world's biggest contemporary art jamboree, as a place where these people circulate "in a giddy round of glamour-filled socialising, from one swanky party to another".

"Do any of these people actually enjoy looking at art?" asks Saatchi. "Do they simply enjoy having easily recognised big-brand-name pictures, bought ostentatiously in auction rooms at eye-catching prices, to decorate their several homes, floating and otherwise, in an instant demonstration of drop-dead coolth and wealth? Their pleasure is to be found in having their lovely friends measuring the weight of their baubles, and being awestruck."

His comments will unquestionably cause waves in a world in which Saatchi has taken a pivotal role.

For some he is the less famous husband of Nigella Lawson but for the art world he is of immense importance. For 30 years he has been a voracious buyer of new art and was instrumental in the success of the Young British Artists movement, buying up the best of the likes of Damien Hirst and Tracey Emin and exhibiting it at the groundbreaking Sensation show at the Royal Academy in 1997.

But Saatchi says he finds the new art world toe-curling. "My little dark secret is that I don't actually believe many people in the art world have much feeling for art and cannot tell a good artist from a weak one, until the artist has enjoyed the validation of others.

"Few people in contemporary art demonstrate much curiosity, and spend their days blathering on, rather than trying to work out why one artist is more interesting than another."

Many will be surprised at the ferocity of his opinions. The Turner-nominated artist Louise Wilson – half of the Wilson twins – said she did not recognise his characterisation of collectors. "Maybe Charles is upset because he is not longer the chief proponent of the vulgarity," she said. "There are more collectors out there as opposed to the late 80s and 90s when there was just one which is a good thing."

But she added: "Many artists and art works have now definitely become a brand in a sense and some people may well go 'I'll have a Koons and a Gucci.' You can see that happening in certain contexts so in a way he does raise some interesting observations."

The curator Norman Rosenthal said it was impossible to generalise.

"It is very difficult to make a good exhibition," he said, "and the real problem is the art world has become so huge. When Charles and I were younger and doing the world of art it used to be much easier to sort it all out."

Rosenthal said Saatchi had put on extremely good shows but also shows that were not so good "and I speak as a dear friend of Charles."

Rosenthal was speaking from Miami where most of the people Saatchi is talking about have gathered for the latest fair on the contemporary art calendar. Rosenthal admitted that if 95% of the art there were destroyed then it would be no great loss.

What effect Saatchi's intervention will have on a buoyant contemporary art market remains to be seen but Sarah Thornton, the author of Seven Days in the Art World, predicted it would change little.

"This is so disingenuous of Charles Saatchi because he is selling art to these people and he is their role model. I find it shocking that he would come out and say this because his gallery has become a showroom for upcoming auction lots."

Thornton said Saatchi had made many millions selling on much of his collection. "He is feeding the people he is condemning." She put his comments down to "misanthropy".

Saatchi has had a London gallery for contemporary art since 1985 in different locations including St John's Wood, County Hall and since 2008 the former Duke of York's HQ in Chelsea.

According to the Art Newspaper's survey, in 2009 and 2010 the most visited UK show was Van Gogh at the Royal Academy followed by five shows at the Saatchi.

In 2010, Saatchi said he wanted to leave the gallery and part of his collection to the nation. A spokeswoman said negotiations to make that happen were continuing.

Expert view: Saatchi's Robert Hughes moment

The first thing to be recognised about Charles Saatchi's Swiftian explosion of rage against the art world is that he is uniquely qualified to say it. The second is that broadly speaking, he is right.

Saatchi is so synonymous with contemporary art that some readers may be baffled by his anger at the current state of it. Surely he is Mr Modern Art? Absolutely, but Saatchi has always been a collector who took risks for artists he loves. His championing of Damien Hirst two decades ago was not an attempt to follow fashion but a genuine act of enthusiasm for an artist widely attacked by critics (then as now) and mocked by the tabloids: he was right.

For me, the moment I first saw Hirst's shark seemingly swim through green formaldehyde at the Saatchi Gallery was when I knew the art of my time had teeth.

Saatchi's brand of provocative art collecting, daring the public to like what he likes, made him the natural patron of artists likesuch as Hirst and Sarah Lucas who, in the punk tradition, did not care what the public wanted and grew great on irritation. Everything is different now because, as he says, there are many collectors, and it's hard to see how they have individual taste or a sense of mission. Mega-dealers such as Hauser & Wirth and Gagosian happily "educate" the tastes of these collectors. Art fairs popularise the idea of art as cool shopping even with those who cannot afford to shop.

Here is the one weakness in his argument. While it is undoubtedly the moneyed global elite and their suck-ups who dominate the art world, there is no revolution at the gates, for art fans from much wider social spheres are sucked into this uncontroversial, irrelevant neophilia.

A broad swathe of the middle class, not just collectors, lap up the videos and pretentious installations he lambasts (he has never collected video), and dismiss any scepticism as "conservative". The art world has taken a lot of innocent people with it on the road to mindless corporate fashionability. It needs an honest critic, and maybe Saatchi's Robert Hughes moment has come. No one can accuse him of being a stuick-in-the-mud.

Jonathan Jones