On the eve of these world championships Sebastian Coe made a claim so startling it stopped some listeners in their tracks. Doping, he said, was no longer athletics’ biggest challenge, rather it was the need to lure new fans. It was as bold as it was reckless and it took only two days to unravel spectacularly with Justin Gatlin’s victory over Usain Bolt in the 100m final – along with the savage chorus of boos that bookended it.

Inevitably the reaction to Bolt’s defeat was binary – the Jamaican the shining knight, Gatlin the super-villain. And no sooner had the boos subsided than there were also dire predictions about track and field’s future. But who could blame the doubters? Two years ago when Bolt beat Gatlin by 0.01sec to win 100m gold in Beijing, the BBC’s Steve Cram had insisted that the Jamaican had saved his sport. What were the public supposed to think now?

Actually we know what they think. They are far more cynical and less trusting – and some of them even suspect everyone is at it. Greg Rutherford, for instance, tells the story of when builders came round to install a long jump pit in his garden – and one of the first questions they asked his father was what drugs the London 2012 gold medallist was on. His experience is not an isolated one. In this environment the happy-clappy approach will no longer wash.

Radical ideas to get to the truth are required. Chris Eaton, who ran Interpol’s command and co-ordination centre before working as head of security for Fifa, suggests the IAAF should even consider a three-month amnesty programme and an investigative truth commission on doping – with a failure to come forward making a subsequent discovery a life ban.

“Dire problems need momentous solutions,” he says. “Lost trust is only rebuilt from trust in solutions. A truth commission is a frightening thing but it’s serious and it works – look to South Africa,” referring to the post‑apartheid investigations. “The doping and associated corruption scandals besetting the IAAF will not be easily fan-forgiven.”

In fairness to Lord Coe he deserves credit for pushing through proposals that led to Russian athletes being banned, and for setting up an independent Athletics Integrity Unit. But as president of the International Association of Athletics Federations, Coe needs to confront every uncomfortable truth, no matter how damaging, and that means being honest about the potential scale of performance-enhancing drugs, which have seeped away at the public’s confidence ever since Ben Johnson was busted at the 1988 Seoul Olympics.

Athletics often feels hard done by – with some in the sport believing they pay the price for catching more cheats than other sports. Some sympathy for that position is fair. But how can the system be trusted given what happened in Russia – and when there is so little testing in countries such as Ethiopia and Kenya? Or when so few doping tests yield a positive response? Officially around 1% of tests prove positive each year but everyone knows it is higher.

Dick Pound, the first head of the World Anti-Doping Agency, has suggested the figure is probably around 10%. One survey at the 2011 world championships in Daegu estimated that a staggering 29% of athletes who competed had taken a banned substance in the previous 12 months. The truth is that testing is the Maginot Line in the fight against drugs in sport – well-intentioned and solid-looking at first glance, yet all too easy to get round in practice.

The IAAF is hardly innocent, however. It was only last year that Gabriel Dollé, the former director of the governing body’s anti-doping department, along with several other senior figures were banned for their part in extorting £330,000 from the Russian marathon runner Liliya Shobukhova to cover up her doping violations.

As for Gatlin, it is hard to believe his claims that a massage therapist rubbed testosterone cream into his legs without his knowledge, which led to his being banned for four years in 2006. Or – given his previous – not to wonder how he was able to run faster at 33 than he was at 23. But he is not the unapologetic arch-villain that he is portrayed. In 2010, for instance, he privately told the IAAF he had “great remorse” regarding his mistakes and he has also gone into colleges to speak to young people about the importance of training and competing clean.

That hardly makes him a saint, of course, and there are athletes who have suffered direct financial losses from his past cheating. But the full-scale pile on seems unfair, especially when there are dozens of other athletes with previous bans in London not getting an iota of that treatment – including Amantle Montsho, the former world 400m world champion who was cheered on Sunday despite a doping ban. As the British sprinter James Ellington put it after the 100m final: “Hate doping, but the media have turned Gatlin into a villain and the masses follow. Do they not realise how many cheats they have cheered?” A glance at the list of London 2012 100m finalists, for instance, shows five of the eight men have served some sort of doping ban.

Incidentally, Coe is absolutely correct to stress the desperate need to get more people watching athletics. It is a fantastic sport, for all its faults. Yet how can it ever hope to have fresh blood pumping through it when too many of the public assume that its soul is frozen and its heart is permanently blackened?