For a sense of scale a total of 177 people have died of vCJD, out of a UK population of approx 60,000,000
Imagine, the UK would adapt this rule.
That's not actually true. There are some restrictions if you're a man who has sex with men, but you're certainly not permanently barred from giving blood.
cf. https://nybloodcenter.org/donate-blood/become-donor/can-i-do...
This is a weird way of phrasing it. More accurate would be: You may not donate if you are a man who has sex with men. The only way to donate is to 1) stop having sex with other men and 2) wait 3 months.
I'd say "you can't donate blood if you're gay" is a pretty close approximation.
As an approximation, yes. But that also includes bi-men, as well as women who have sex with bi men.
As such, your formulation also lacks precision, something you took me to task for (despite my link to actual data) in the previous sentence of your post.
Personally I think it's a dumb restriction given the advances in blood testing, but I don't run a blood donor program.
That said, those who deal with blood and blood products to be given to other humans tend to apply broad filters for donor acceptance. Note all the other restrictions in the the link I posted.
While extensive blood testing is the norm these days and the sensitivity of such testing is much better than it used to be, I imagine that being so picky about donors is much more about maintaining the integrity of the blood supply than being biased against any particular group -- even if it might seem that way.
Especially since the lack of screening/testing in the past caused a huge amount of suffering and death[0], including my own brother in-law, and through his exposure to tainted blood products, my sister as well.
Please note that such tragedies (with Hepatitis, HIV and other blood-borne diseases) are most certainly not the fault of donors.
Understanding the history[1] of these issues provides a lot of context (as it does for most things we do) for what we do today WRT the blood supply