I agree with the writer's perspective on this situation.  Brexit was indeed political folly of the worst kind.  But I also wonder if another reason for Brexit was the constitutional changes that granted  assemblies to Scotland, Northern Ireland, and Wales, while denying an assembly to England.  Those new  assemblies reinforced the national and cultural identities of the Scottish, Northern Irish and Welsh but without an assembly of their own the cultural anxieties of the English became focused on the EU, and the Brexit vote became a kind of misguided cultural defense.  Perhaps if the English had been granted their own provincial assembly their cultural anxieties might have been assuaged and the Brexit vote would have had a different result.