I'm not sure I have a big problem with this. If you do business with a company that can just disappear, that'd be a bummer. That said, you shouldn't do business with a company like that, but people aren't always smart.

My point is that the UK isn't immune to diseases being transmitted via blood donations as you implied.

That's not my point. It wasn't screened for until it was known about, which means many people contracted HIV through blood transfusions. The same thing can happen with another new disease that they don't know about, which in turn means they aren't screening for.

Until something comes along that isn't screened for. HIV comes to mind.