I think both explanations are valid, and I really think the second explanation rings true. I think after two decades of instability, those mechanisms that are successful, that actually work, are often mechanisms of “take what you can, and take what you can by force while you can”. I think it's tragic, but many of the more traditional economic systems have begun to disintegrate as a result of this sustained insecurity, and what has emerged is an adapted system of economic opportunism that involves starting a rebel group.
One of the sadder things I saw on a recent trip to DRC occurred when I was with my Congolese mentor, Justin Kabanga, who is head of this psychosocial assistance organization. We were in a car together on a remote rural road, and two seven-year-old boys had pulled a string across the road, and we slowed down because they had created a very small roadblock. We rolled down the window and one boy asked for money, and I was horrified because this was seeing a young generation of Congolese boys mimicking what they saw as what men did.
It really created an interesting conversation with Justin about what kinds of jobs.... Some children play store, and these boys were actually playing rebel group. I think what people often do is that they see the most viable way to make money is to create these semi-politically motivated, but mostly just opportunistic, armed groups.