It may not, however, be for exactly the reasons you imagine. Lucas Skoczkowski (pronounced "Scotch-cough-ski") says it's because the operators are having big problems with the copper actually being stolen out of the ground.
This is an issue in Africa, the Carribbean, and some Asian markets. "The wire gets stolen," he says. "They just dig it out of the ground and sell it to China." Doesn't matter if it is copper or fiber naturally because the thieves can't tell 'til they have already dug the stuff up.
— Dan Jones, Site Editor, Unstrung