On top of that is that the UK has had a different currency whereas in the rest of the Eurozone everyone uses the same currency. It's so easy to go to Belgium and just use whatever's already in your wallet. Like a country like France or Germany or Sweden leaving the Euro would be a much much bigger deal than Britain, which I don't think really integrated as well with everyday people as they do on the continent.
I'm not saying it is not a step back, but I doubt it will be the end of the west as global leaders some people are portraying this.