I would hope that a branding specialist would have no trouble understanding the Brexit result. It doesn't require deep analysis. Remain mounted a campaign that was defeatist and based on fear: "ok, our attempt to negotiate resulted in nothing at all, but we must still remain and obey Brussels because if we don't our friends and allies will destroy our economy."
As a logical consequence, they were effectively arguing that there was no future for British democracy, because the trend over time has always been for the EU to take more powers out of the hands of democratic local government and take it for itself.
That's a terrible brand. Leave campaigned on a better future with "take back control" as their byline.
You don't need conspiracy theories about corporations with mind-control machines to explain what happened next.