Good post Rasc. In summary then, it’s because all anti-vaccers are idiots and most idiots are pro-Brexit.
I don't think they are necessarily idiots just misinformed and the victims of propaganda.
Goebbels famously said “If you tell a lie big enough and keep repeating it, people will eventually come to believe it. The lie can be maintained only for such time as the State can shield the people from the political, economic and/or military consequences of the lie. It thus becomes vitally important for the State to use all of its powers to repress dissent, for the truth is the mortal enemy of the lie, and thus by extension, the truth is the greatest enemy of the State.”
If you are aware of the above and can keep an open mind when confronted with the propaganda being propagated then most people (hopefully) will see it for what it is, a lie. There are people though who will fall for it and be taken in by it. We have to look no further than what is happening in the USA at the moment to realise that is a lot of truth in Goebbels statement.
I do believe this has come about because of the education system. When you have an Education Minister like Gove who champions rote learning over critical thinking then you will end up with a population who can tell you when, but cannot explain why. It is all very well knowing for instance that on a certain date, a certain event happened, but if you cannot explain why that event happened then knowing the dates becomes superfluous. The same things happened with BREXIT in my opinion, you have a dumbed down populace who know certain things happened but don't know why they happened. This is not just a Pro-Brexit thing either , Pro-Remain was exactly the same, they both used manipulation to distort facts knowing that the lack of critical thinking would mean that there positions went unquestioned as they were related to things that the population did know, but hadn't thought about in depth because they lacked the skill of critical thinking.
When you get a debate like Brexit, the sheer enormity of it means in my opinion it is virtually impossible for a person to be totally across all the angles. They will take parts of the debate that they do know that reinforces there beliefs, they do it without questioning there beliefs because they have been taught in a rote learning fashion that, that is that.
That then leads to the tribalism, people identify with like minds, if that like mind also has a penchant for anti- vax, then that position becomes appealing to the others of like mind because of rote learning, it becomes a fact that goes unquestioned because of the lack of skills to evaluate it with critical thinking.
Of course my view may be wholly wrong and it is far simpler than that because i lack the skills to evaluate what has happened in a critical manner, because i also have my own inbuilt bias and i am not immune to being propagandised. We all have our starting points and its what we come across on the way to our end point that is important, a lot of that though will be confirmation bias. We all like t think our position is correct and will look for evidence that supports our position.
On a different note it is one of the reasons i believe referendum is poor democracy, it is wide open to manipulation due to lack of knowledge. In a representative democracy we elect people to do our thinking for us and should in an ideal world trust that those people have our best interests at heart and have the requisite skills required to make sense of complicated debates. Of course those people though are still as open as any of us to Goebbels premise