I had no idea the 'benevolent colonialist' trope still lived. Thanks Tabby you're like a dinosaur skeleton in a museum.
Have a little read about Julius Nyerere. He's was a bit of a teenage hero of mine (ignore the weird Hitler moustache). There were great African leaders post-colonial era but they were hampered by being left a terrible colonial legacy and ongoing interference in the region (including debt, cold-war being hot there, American interventionism, tied aid, war in other regions spilling over, the IMF and World Bank, Western support for South Africa and other terrible regimes, existing tribal and border issues instituted in colonial times, and a host of other issues).
An should we all go around feeling guilty? No. But when there are discussions about immigration, health tourism, illegal wars, Ebola, racism, prejudice, Black History Month, maybe take a tiny pause and think, "where does my initial feeling come from?"
And I take people's points about being Scottish, Irish, living in poverty in the UK. My family isn't English. And we certainly weren't rich at the time. Lots of miners and mill workers and farmers. And no one said, "everyone feel guilty". But examining racism and privilege is important. We still live in a world with Steve Bannon and the Daily Mail. It's a good idea to think critically.