To say that British colonialism was better in Nigeria than in Kenya, or than Belgian colonialism doesn't _really_ seem to support the thesis that "there were good things about British colonialism", does it?
The fact is people showed up with guns one day and said "you work for me now" and "all these separate tribe lands are now one administrative unit so I can manage it better". No matter how nice they were by building roads (to ports), or schools (so the workers can understand basic math and thus follow orders, and how great their lives are under colonial rule) doesn't change the highly likely correct statement that an independent Nigeria free from influence stirring internal conflicts would have been much better off.
"Being colonized was better than living through our internal struggles" is kinda moot. Europe had plenty of war, disease and more war and still came out through it. A colonizer imposing stability by the sword/rifle wouldn't have been better in the long term.