equilibrium exchange rate in the foreign exchange market if often unfavourable to less developed countries. why?

It is seen that the the less developed countries depend to large extent on the developed countries for the export of the sophisticated and modern technology, plants and other such technology related imports. Many a times, this results in a situation of negative BOP for the less developed countries. Accordingly, their foreign exchange reserves fall short of the requirement. That is, the demand for foreign exchange exceeds the supply for foreign exchange. This results in a high exchange rate (i.e. low value of domestic currency as against foreign currency). Thus, we can say that  the equilibrium exchange rate is often unfavourable for the less developed countries.