One can argue that the quantitative targets are well suited to a certain type of economy facing specific challenges; notably a low income economy with a very shallow financial sector, inadequate international reserve cover and for which the key macroeconomic challenge is to restore macroeconomic stability after a period of severe macroeconomic turbulence.
This was the situation on Uganda in the 1990s (as well as many other SSA economies at that time) and still applies to some countries in SSA today. However, the economic situation in several SSA countries has evolved radically in the last two decades and they face very different macroeconomic challenges to those faced 20 years ago.