Farm Subsidies Good for Africa?

Thanks to Marginal Revolution here's an argument for farm subsidies, at least on food.
Africa does not need more expensive food:

"The trouble is that the truth is a little bit too simple to be credible. Farm subsidies in the EU and USA mean that we sell some kinds of foodstuffs (mainly grains, milk products and sugar) to Africa and other countries cheap. So cheap, in fact, that the Africans etc can buy our imported goods cheaper than they can produce them for themselves. This is good news.

No, stop, yes it is. If you can buy something for cheap, then that is good news. Food being cheap is good news for Africa. It isn't bad news. I promise you it is as simple as that."

Not sure I agree fully. We may be making life harder for African farmers and easier for African city dwellers. There's still many more farmers, see here.