I don’t think the idea of us bringing civilisation to barbaric people is limited to retrospective analysis. It was a notable factor in expansion of the empire when it was happening. The idea of 'ethical imperialism' was quite prevalent, especially with people like Chamberlain. Although I always liked to believe our empire was part of a grand plan to export ‘Britishness’, upon reading, it does seem to me the colonies and dominions, perhaps apart from India, started out merely as outposts from the early colonial age, or havens for the surplus populous of Britain, without any intention of expansion. South Africa for example was simply a stop off point, a service station, on the way to India. It was purely Co-incidence that Rhodes found diamonds there and turned it into a money making machine.
We certainly did accelerate the rest of the world’s industrial development, exporting our industrial evolution upon them. Something the rest of the world should be thankful for in my opinion. Another key moral bonus of the Empire was its insistence on the abolition of slavery. Not only did we make it illegal, we encouraged other countries, such as Portugal and Spain to do so as well, and compensated them for the trouble.
EDIT: When I said ‘is limited to retrospective analysis’, I meant to say it IS NOT. I'm such a dumbass!!! I've got a bad habit of typing exactly what I don’t want to say, and saying the complete opposite of what I believe sometimes, which can end up being offensive :|