Colonisation is OVER

European countries have colonised and used Africa's land and people for some time, from the Portuguese to the British, and yet we've stopped trying to "take over" African countries.  Contemporary times seem to be focused on reparations or dealing with the consequences of colonisation, instead of continued use and exploitation of the land.  Why?  Is the land that shitty that agriculture won't continue to thrive?  Are the people that lazy that they can't force everyone to work towards industrialising civilization? 

Also, how can we terraform dry and arid land into fertile soil in order to grow crops?  This applies to Africa, the middle east, and parts of asia.  There is so much unused land, so why can't it be infused with nutrients, fertilizer, nitrates, etc.

big businesses WANT to invest in places that have political instability

No, they don't. They want to invest somewhere where they can get stinking rich. Political instability means risk, so unless they stand go gain lucrative returns, they'll go elsewhere. In the case of Iraq, it's going along with the US porkbarrel, or grappling with OPEC. China is receiving investment because their government is opening up to them, and they have bother infrastructure, an educated population, and dirt-cheap rates.

Africa apparently doesn't offer enough to interest businesses for the time being, otherwise you can be certain they'd be investing. They don't care about people or cultures, what they care about is maximizing return. If Africa offered them that, they'd be all over it.