Lily Allen: From Riches to Rags, Channel 4

Why were any of us watching Lily Allen: From Riches to Rags last night, about the pop star's move from selling millions of tracks to stacks of vintage clothes? It was not because we need a lesson in the hardships of starting up a business - Allen bought all the stock out of her musical profits and her office was thick with roses. No, it was because the real intruded into a reality show: this was not car-crash TV - it was miscarriage TV.

Any rubberneckers waiting to be entertained would have been disappointed by last night's first episode: we had a promise of tragedy at the start, and the announcement of her pregnancy was trailed at the end, but there was distinctly little grief. Keep those hankies gripped tight, though: it's coming.

The overriding emotion was anger, as Allen's sister Sarah helped her get the business off the ground. Lily thinks Sarah is feckless, Sarah is resentful of Lily's free-spending, Lily dobs her brother in to their mother for playing a violent computer game, Lily storms out of a market-research session as Mary Portas puts on her grown-up face for the camera.

If that camera had not been intent on capturing the sororal conflict, it would have mined the much more interesting seam of Allen's own reasons for going into business. It was not that she was tired of fame, adoration, money and acclaim (as the awards scattered around her office announced); it was much subtler and sadder than this: she is sick of the pop star's peripatetic life. The shop for her, it seems, is an anchor, and it might as well be selling fish or fowl instead of frocks, as long as it keeps her in one place.

There is only the small matter of actually setting up and running the business to overcome, then. Luckily, Allen can employ Portas as a consultant and can hire a fashion luvvie as a brand manager, a woman who has been so immersed in the high-end rag trade that she can say, without irony, "I'm so post-burlesque." At one of her concerts, a fan praises Allen for being genuine, and in her tart and revealing lyrics, she teaches a valuable lesson about uncomfortable truths. With this programme, however, Allen's insulation from the rest of the world is painfully obvious, and her common touch disappears.

All the problems Allen faces when starting her shop are dull, the sort of fluff that can be overcome by throwing more money at it or having a therapeutic cry. The only reason to watch, therefore, is because you are jonesing for a celebrity tragedy, the sort of first-hand insight you can't get from Grazia.

Perhaps Allen's miscarriage - for which stay tuned - was a cruel deus ex machina, something awful appearing out of nowhere to turn a dull series into a can't-miss programme, viewers waiting, gawping for the tears and the trauma. Without the miscarriage, would Channel 4 have shown this, or would it have been relegated to its home for teen tedium, E4? Any compulsion to watch does not come from Allen's personality or business nous, but from the imminent tragedy - and that is inhumane.

• Watch Lily Allen: From Riches to Rags on 4oD
• Find Lily Allen's music from Amazon