You could say that all those people have been wrong before and therefore could be wrong this time. But, the problem you don't mention is that there is an eleme

You could say that all those people have been wrong before and therefore could be wrong this time. But, the problem you don't mention is that there is an element of self-fulfilling prophecy to those statements. There is no absolute objective metric that measure your country in a negotiation, it is more a market type thing. There is an element of irrationality and if all your partners think you are in trouble, then they will act toward you are if you were in trouble which may well be cause you to be in trouble. That works at all level too. If enough people living in the UK think the UK is doomed, they will start saving money or investing in foreign countries. A slowing of consumption is a crisis, it does not matter if the slowness was caused by objective and rationale reason or not. You can already see the effect. The last budget was another austerity budget with cuts and no investment. Despite the supposed economic nirvana that is only a few months away, the government is nevertheless bracing for trouble and that will affect the British people negatively regardless.