1. They're talking about the current situation, but you're bringing up history. 2. Given the lessons from the past, why would you still want to do something this dangerous?

Cost, or availability due to cost. Still a driver in developing countries.

From the WHO article linked to by GP, the issue is that patients also insist on injections over oral meds.

That's driving the insistence on injections, and rural doctors/clinics cutting corners.