I think you will find Lagos and Abuja are some of BAs best routes because of the oil industry guys flying Club. They won't be withdrawing from the route anytime soon.
Most of the Nigerians I have met were honest, smart, savvy people who were as embarassed by their 'ruling classes' as I was. The low level baksheesh is no worse than in many countries where the poor don't earn enough to live.
Don't judge a country, especially a poor country, by the people flying in and out of it!