Actually, I can prove you wrong...
IQ Deficit is NOT a cause of bankruptcy and a failed state.
Consider this: You can have 900 people in an airbus, with no knowledge of aviation at all. You just need ONE PILOT and all those people will be safe. The problem comes when the 900 people want equality and ask why should that ONE person be in charge of everybody, and INSIST that THEY want the power to make the decisions. Suddenly everybody, INCLUDING the pilot are screwed.

So, absolutely not: IQ is not the problem. But when people with low IQ's are placed in roles that require spectacular intellect, just because they insist on equality, THAT'S when things start crashing. Understand also, I don't mean this as a black/white issue. Just: People have different roles, talents, different destinies, and make different decisions about their own futures.

If you put the gardener in the cockpit JUST for the sake of a BEE rating, then you better have a parachute ready... ADD to that: If said gardener wants to "test his wings", asserting himself, and make himself "count" by forcing strange decision with no logical grounds, against the advice of the pilot sitting in the passenger seat "just because I can": THAT'S when things go wrong...