I mean, can you believe this?
https://cdn-images-1.medium.com/max/1800/1*piGY6KAwYsDSweClC...
https://s-i.huffpost.com/gen/1521502/thumbs/o-SUN-FRONT-PAGE...
On top of that it has been proven that the leave campaign lied and broke the law regarding funding.
Like that David Cameron clown, for instance.
I think one can. Britain is a democracy. An old one. If one votes for a dramatic departure from the status quo without asking how it will be executed, that's a failure of civic duty. Voters own a share in their democracies' successes and failures; economically, politically and morally.
As an aside, I think terms like 'jingoistic' aren't helpful to discussion. I've never quite understood why it's jingoistic to prefer UK sovereignty but not jingoistic to prefer European sovereignty.
They actively chose something that you say was poorly defined but which was widely understood to be a very dramatic and potentially dangerous shift for the country. If you can't blame them for picking a poorly defined option out of some jingoistic notion of what the UK should be, what can you blame anyone for?