I'm really all in favor of simplicity for myself (when I can make it a way of life that I like), but I will not defend it for people so poor that they can't weather the simplest life accident. And my feeling is that there is a lot of africa's misery summed up in "can't weather accidents".

In Cameroon, I met (and worked with) locals who were at the european standard of formation/knowledge and job skills. I also met (and employed) people who were living for CFA 10k a month per person, even when I paid them above the local minimum wage.
I talked to middle class people who were telling me how hard it was to get jobs, and at the same time, I could see basic infrastructures missing, or badly maintained (roads, water, electricity). I had interesting discussion with my fellow colleagues (who I believed quite liked having them) about why houses were not made of stones in mountain countries but in imported cement, or why the city was not employing people to clean sewers (no tax, no money, no job).

I still have problems to understand why, appart the technological side of development, one country doesn't manage to build and maintain structures that could be found in antic India or medieval Mali, like waterways, houses. I feel it is for the lack of legitimate power in these countries (where the gov is often backed by former european colonisator).

In Cameroon, there exist a small city/country where, at the beginning of the XXth century, the local king forced a small scale modernization of its country, some ten years before colonization. He tried to get from a rural village to an urban center, with written-royal acts, simple technologies to better the farm output (like corn smasher), and commercial/political domination of the area.
It didn't work in the end, because he was overpowered by the europeans (french and germans). I'm convinced that there could be african leaders of that kind today, who would make the "enforced simplicity" a chosen one, or more, but not only a european view of what simple (but happy) man should be on the earth.