It may sound like a later model of iPhone, but nobody is likely to confuse G4S with the 3GS.

The latter was, on its launch, praised for its sleekness, efficiency and for being capable of delivering data at twice the speed of its predecessor. By contrast, G4S is cumbersome, inept and, as we discovered last week, probably incapable of delivering pizza, let alone the 13,700 "highly trained" security guards it had undertaken to supply for the Olympic Games.

It beggars belief that at a time of high unemployment, and with all the notice everyone involved has had to prepare for this shindig, the Government is now having to bring in the troops. Troops, by the way, who will have had their leave cancelled after returning from dodging snipers and improvised explosive devices in Afghanistan, many of whom will be handed their P45s as soon as they've helped salvage this glorified school sports day.

Now that I have seen a photograph of Nick Buckles, the grinning ninny who (at the time of writing, but I'll warrant not for much longer) is chief executive of this shower, it further stretches my credulity that we were proposing to hand him millions of pounds of taxpayers' money.

But it doesn't surprise me in the least to learn that by last December, when it signed the deal to bring in more guards, G4S's programme management costs had risen from £7 million to £60m, and its operational costs from £3m to £65m. Since last week's disclosures, some £200m has been wiped off its value. It was, however, astounding to discover that the company (which, in the days when it was Group 4 and Securicor, was usually heard of when prisoners in their care escaped, which was often) is the third-largest private sector employer in the world.

The rising costs, and their scale, however, are merely par for the course for any grand project involving government spending of public – ie your – money. I suppose it is a sort of improvement when the inevitable overspend is a private contractor's liability, but the fact is that colossal beanos like the Olympics practically never generate the benefits which are claimed for them.

The vast majority of Olympics have cost their host countries money. Sydney, which was regarded as reasonably successful, cost the Australians AUS$2 billion while Atlanta, though it made money by being – at the time – the most nakedly commercial Games ever, only produced a profit of $10m on an investment of £1.8bn.

Nor does the much-vaunted "multiplier" effect of value being added to the areas "regenerated" by the infrastructure thrown up for the Games bear much scrutiny. Many sites, by their nature, have very limited use beyond their purpose – velodromes and dressage enclosures, for example – while it would be considerably easier, if one wanted to improve housing stock, simply to build some flats, rather than having them serve as an Olympic village first.

Nor does it seem to do much for tourism (visitor numbers to New South Wales fell after the Sydney Games), though it will certainly ensure London grinds to a halt for the next few weeks and becomes even more of a hellhole than usual. In part, that is because its poor citizens, at the behest of Locog, the organising committee, will have to endure constraints on their movement, liberty and even freedom of speech which almost make North Korea look like the land of the free.

Some of the more absurd of the recently reported examples are the fault of the sponsors. McDonald's attempted to protect their role as sponsors by introducing a prohibition on any other food outlet selling chips (unless it was with fish). Because Heineken is the official beer of the Olympics, no British beers will be in evidence. Apparently, John Smith's bitter and Strongbow cider will be available, but rebranded as "English ale" and cider tout court – despite the fact those particular brands are owned by Heineken. Small independent traders have been bullied into removing window displays which might be thought to allude to the Olympics, and threatening noises have been made about anyone using words such as "Games" or "London" or "2012", all of which seem to have become the exclusive property of the Olympics and its sponsors for the duration of the summer.

But much of it is simply down to the overweening arrogance and ridiculous grandiosity of the International Olympic Committee. Pandering to these windbags, who are as pampered, overpaid and self-important as any UN diplomat or delegate to a meeting of the World Bank, has led to the roads in London being repainted with lanes for the exclusive use of their limousines, and guided missiles being mounted on the blameless roofs of flats in the East End for their protection.

From the time of the Baron de Coubertin, the educational sociologist and all-round charlatan who founded the modern games, the Olympics has never undersold its own importance. The list of requirements for countries hosting the contest is staggering in its arrogance (the Games must be opened by the head of state, for example). It is accompanied by a long roll-call of, for the most part entirely imaginary, benefits, described in the loftiest terms.

The connection with the ancient Olympics is almost entirely spurious. The cult of amateurism, of which one used to hear quite a lot, even as recently as the 1980s, has long since been exposed as the most ludicrous sham. The idea that the Games foster understanding, peace and concord between countries is preposterous (remember the Moscow Olympics?). Even in the ancient world, the peace generated by the Games was a temporary ceasefire.

Fortunately, it is not too late. The dismal weather which much of the UK has had throughout what is laughably called the summer gives us the opportunity to think again. Nothing is more natural than that a school sports day being cancelled if, as my old PE teacher was fond of declaring, "the weather is inclement". The weather is literally inclement, the metaphorical climate is highly unsuitable and the event itself is a waste of time organised by pompous show-offs. Let's call it off.