I saw that Benjamin Zepheniah on TV, saying the Monarchy should be abolished because the Royal Family had blessed slave ships.
What he didn't bother to say is that pretty much the entire world (including Africans) participated in the slave trade at that time, and that Britain had taken the lead in the fight to stamp out slavery. The first time in history that former slave-holders had fought to free slaves. Literally fought, with warships blessed by the Royals.
So yeah, we've done some terrible things - but on the whole (even under New Labour) the UK is a powerful force for good in the world, and we deserve credit for that. And we're to "undo" the effects of everything we've done... Well let's say that Zepheniah wouldn't be sitting in an air-conditioned TV studio wearing a handmade suit, hatin'.
If they start apologizing to people one by one... that'll take a while.