We'll have no-one to blame but ourselves.
I'll have a good go though 
I do blame Dacre, not so much for what is being published now, as for the years and years and years he spent othering the EU. Long before it was routine to other Muslims, immigrants, refugees the way that it is now normal to do. Just the simple measure of writing about 'the EU' and 'Britain' as if they were two separate things, usually at odds, and that our membership of the EU didn't actually exist. Of course, if there was anything positive 'Britain' had done it. If there was anything negative 'the EU' had done it, without 'Britain's' involvement. Like Noel Edmonds and his cosmic ordering - live and behave as if your goal has already been achieved.
What is true, though, is that if it had really been his fault, it would never have worked. Lots of people agree with Dacre and his cohorts. I'm a Remainer and a member of the metropolitan liberal elite and I wasn't particularly enthusiastic about the EU, it had a hell of a lot of problems and seemed to be becoming a religion of its own. But I have read a bit of history, and I certainly thought it was stratospherically better than what I do think is the inevitable alternative, which is war. I know that there are many who felt that the continued existence of the EU will lead to war as well, probably with Russia, and they are just as likely as me to be right.
What I think will be bitter in a few years is if the EU collapses, or perhaps continues in a shadowy rump form, I will always think that it was Brexit's fault. Which I know many people won't agree with, they will think it justifies the Leave vote as we would have been 'dragged down' by a collapsing EU. I think we ran away from our neighbours, thinking we could indulge in a fit of nativism in the same protected environment we have been in for forty years, only to find that everyone else is being nativist too, funnily enough.