Has Cowell finally lost his touch?

It should have been the TV event of the season. When The X Factor US, the music mogul Simon Cowell's talent show, hit screens last month, it had already scored a level of publicity that could make a president jealous.

First came Cowell's very public dumping of his old chart-topping show American Idol. Next, last-minute changes to the show's judge line-up grabbed yet more tabloid headlines, as it said an abrupt goodbye to the British import Cheryl Cole and hello to the Pussycat Doll Nicole Scherzinger.

Finally, Cowell's stiff, ageless face appeared on just about every major US chat show in the run-up to The X Factor US's September 21 debut. With a launch like that, the new show was surely on target to break television history. Wasn't it?

In fact, the first episode on Fox wasn't even the hit of the night - it came second to the sitcom Modern Family. Crucially, the new singing competition scored fewer than half the ratings of American Idol's debut earlier this year, the first Idol series that has run without Cowell peddling his familiar Mr Nasty routine on the judges' panel.

With 12 million watching, X Factor's debut was hardly a flop, but it fell far short of the 20 million viewers a US debut show needs to count as a surefire hit. Last week figures slipped yet further, with an 11 per cent drop in viewers from its debut. Exactly why Cowell's new baby met such a lukewarm reception is still a matter of debate. Had he misjudged his new show? Or is the public simply bored?

Certainly, X Factor has little new to offer, not least because it's a format that Cowell already rolled out years ago in the UK. The programme may have a broader age limit (anyone age 12 and over) and an audience during auditions, but it's essentially business as usual, with the same heavily signposted emotional highs and lows manufactured as American Idol and its clones.

The judges have also made little impact. Comments from Paula Abdul, imported from Idol, invariably seem stale and formulaic, while the music mogul LA Reid - one of the men we have to blame for Justin Bieber - has clearly had a humour bypass. And while the former Girls Aloud singer Cole appeared promising in the first episode, she was quickly replaced by the monotonous Nicole Scherzinger, whose wooden performance led Entertainment Weekly to note that "she couldn't even descend a staircase with sincerity".

These misfires aside, The X Factor US is mainly a victim of Cowell's success. Since his first show - Pop Idol, which launched in the UK 10 years ago this week - Cowell's talent show formats have all but taken over the entertainment world. With pricey audience phone lines and tense live sing-offs now familiar from Poland to Panama, X Factor-style shows have smashed ratings records and made their audiences feel powerful by giving them a direct hand in making tomorrow's pop stars.

Still, enough is enough. So ubiquitous have these shows become that their trademark mix of emotional uplift and cruelty is getting dull. Wherever you are in the world, you can guarantee that any show cast in the Cowell mould will include a weeping contestant explaining how they're doing it all for a dead, sick or poor relative: this person will go through. A tone-deaf social misfit brought on to have their delusions of musical talent destroyed for the audience's amusement: this contestant will not go through, but may be brought back at the end of the series so everyone can laugh at them again. It will also feature a female judge so moved by a performance that she is obliged to dab away non-existent tears, usually after someone has knocked off some Mariah/Whitney-style vocal acrobatics.

Of course, this formula has unearthed some talented singers, but it has also created many failed stars whose tearful, glitter-strewn finales have often been followed by complete indifference from the album-buying public. And with mini-scandals erupting, such as that of 52-year-old Ceri Rees - invited back on to X Factor in the UK two weeks ago after three previous failed auditions, only to be pointlessly snubbed one more time - audiences seem increasingly aware that Cowell's shows are more about snuffing out dreams of stardom than about fulfilling them.

The heavy-handed Cowell mix of syrup and vitriol is looking pretty shop-worn - is it really so surprising that bored US viewers increasingly prefer the warm-hearted fiction of sitcoms such as Modern Family?