When it comes to Africa, asks Andrea Bohnstedt, why do the rock stars and do-gooders think the normal rules of business do not apply.

Time for a rockstar update, I think.

Because this could indeed be the last stage of evolution, the one where pigs do finally fly: Right there in front of me, on the pages of the Financial Times, was Bob Geldof's transmogrification from charity fund raiser to investment fund raiser: Together with two proper finance people, the Bobster aims to raise US$750m for his '8Mile' Africa private equity fund. What next? He will get a haircut? Hell will freeze over?

I shouldn't snipe because I have always argued that those rockstars should get their heads out of their charity tunnel vision on Africa and try to understand that, just like anywhere else, business happens here, too. And also invest rather than donate.

My friend Miles – who has happily and profitably invested in sub-Saharan Africa for many years, thankyouverymuchwithchips – had this to say: 'For twenty-five years he has enraged African businessman and made it difficult for them to attract investment by telling the world that Africa was a basket case. Now, ten years after Africa became one of the fastest growing and most promising regions of the world he has realised that investment, not charity, is what Africa needs. Those of us who have been making good returns for many years by investing there are delighted that he is joining us.' Snap!

Obviously Mr Geldof wasn't the first to discover African private equity – these days, you can't set foot in any of the sleeker Nairobi bars without stumbling over a private equity person or two, common as muck really, and even all those 'social investment' people want to come and play with the pin-stripe suited big kids. It's almost like microfinance: Must. Do. Something. About. Africa. But better late than never, I say

Bono, the other hallowed saviour of the continent ('what's the difference between god and Bono? God doesn't think he's Bono') is also a partner in a private equity fund, Elevation Partners. Their website says that they invest in the media and entertainment industry. Not in Africa, though, it seems – maybe Bono was too busy hitching lifts on Mo Ibrahim's jet and just didn't have the time to look at the exciting and award-winning start-ups in Kenya's tech industry. But it's not as if he hadn't tried his hand at Africa business at all.

Together with his wife Ali Hewson, he launched Edun, an ethical clothing company, in 2005. I stumbled over Ali Hewson and Edun recently when their efforts to have school children in Kibera design t-shirts - child labour, anyone? - were covered in a newspaper article. Since then, the census data have taken much of the poverty glamour off Kibera as it turned out that there are considerably fewer people than the always cited one million in Africa's most notorious slum.

But back to Edun: The Wall Street Journal just helpfully pointed out that Edun, founded to do sustainable fashion and revive the apparel industry in Africa, had in fact just relocated most of its production to China. Now how did that happen? The authors say that despite its ambitious beginnings, Edun quickly ran into problems with low-quality and late production, and sales deteriorated. While initially hundreds of retailers had stored the brand, last year only 67 were left.

The WSJ article is a delight, full of the most fantastic little gems. When production quality was unsatisfactory, the company once “hosted a party in the dark ... to draw attention away from the clothes.” Ali Hewson, the article cites her, was ''naive' about what it took to build a fashion brand: 'We focused too much on the mission in the beginning.'”

But my favourite is possibly this section: “Ms. Hewson says she considered pulling the plug; the couple consulted with friends like Jeffrey Sachs, the Columbia University economist, who encouraged them to stick with the project. “We felt if we failed it would be a double failure. We'd be saying, 'We can't do this,' and then other companies would go, 'Well, see? We've always known that,'" Ms. Hewson says.”

No honey. This may come as a rude shock to you, but serious business doesn't actually look towards Bono and wife for practical instruction and guidance on the apparel industry in Africa. And taking advice from Mr Sachs, the man who is practically incontinent in his demands for more aid: is that sensible strategy?

So let me recap: They had a nice idea with lots of fluff about organics and ethics and sustainability, but little concept of how to build a fashion brand as a business. And, I deduct from the article, were not hands-on enough to control the production process. They take advice from Jeffrey Sachs. This business would have failed anywhere in the world. But they think that it's ok to just rock up in Africa with such a half-baked concept and expect to succeed? Because it says Africa on the tin?

I can't wait for the day when people buy goods and services not because they are, tug heartstrings, from Africa, but simply because they are really good. Manufacturing here isn't easy, we all know that. But it's possible. If you apply yourself to it.

Edun has since sold 49% of the company to luxury conglomerate LVMH Moët Hennessy Louis Vuitton for about US$7.8m, and has hired a new CEO, Janice Sullivan. Ms Sullivan is quoted saying: "So you can see how this brand, in the wrong hands, could go haywire." Indeed.

And Bono might want to stick to the day job: AltAssets write that Bono was recently named as the worst investor in the US by financial blog 24/7 Wall St, which refers to Elevation as “arguably the worst institutional fund of any size in the United States", which has made “an unprecedented string of disastrous investments which even bad luck could not explain".