You make it sound like everyone who immigrated from the Windies from the 50s to the 70s has been specifically and vindictively booted out when ... well, nothing

You make it sound like everyone who immigrated from the Windies from the 50s to the 70s has been specifically and vindictively booted out when ... well, nothing like that has happened at all. Sure, there have been quite a few unfortunate and well-publicised outlier cases of people situationally caught between bureaucratic cracks, but as someone who lives in London, I assure you that thousands of long-since immigrated grandparents aren't getting booted out to satisfy some arbitrary ‘anti-immigration’ whim. It's a mess for sure, but I'm not sure it's as you appear to be trying to paint.