I've always loved the idea of the British Empire being a melting pot of cultures and people. It would have been nice to have had a situation where there was free movement of people between all nations under the British Empire. Why didn't Britain take a similar approach to France in this respect?
EDIT: Someone commented that "We did. It's called the Commonwealth". The Commonwealth of Nations is not what I mean though. French Guiana is an integrated part of the European Union. It's literally part of France in all respects but geographical location. Why didn't New Zealand, Australia, India, Kenya, South Africa, etc. end up with a similar arrangement and be fully integrated parts of the UK?
French Guiana has a tiny population, receives enormous subsidies from the French government (giving the territory one of the highest standards of living in South America), and France itself wants to keep it as it is a good location for its space port. The former British colonies you listed have much larger populations than French Guiana, with their own concerns and often their own serious grievances against the British - and clearly post-war Britain had no interest in subsidising these colonies to keep them in the Empire. This situation was the same with the vast majority of France's former colonies so I really do not see a huge difference in policy or approach to the end of empire between these two nations.
Sources:
Brendon, Piers (2007). The Decline and Fall of the British Empire, 1781–1997. Random House.