A national airline is simply a way for politicians to make money. Bribes get taken from suppliers, contracts entered into which may not make commercial sense, assets sold cheaply, workforce gets bloated with connected but incompetent people. Unviable routes are maintained "in the national interest". Tickets get given to friends and relatives.
Even private airlines battle with red tape and demands for money under the table, eg if an aircraft is grounded while a part sits in customs and they want a couple of hundred dollars or wait two weeks what are the managers going to do ?
Add in poor infrastructure and shortage of skilled manpower and it's a wonder any of them make a profit at all.