The EU started out as a good idea, but when in the wrong direction. The EU was suppose to only allow countries that had similar economies, GDP, unemployment, wages, etc. But the EU starting adding countries that didn't have any of that, who's wages were far below that of other members, who's welfare was far below that of other members state, who's unemployment was higher than other members states, etc. So had the EU only let in members who economies were similar to those countries already members, I don't think you would have say a Brexit vote.
So in the end the EU had nobody to blame but themselves for not listening to the concerns of the PEOPLE, we are starting to hear Swexit, Frexit, and on there are many countries where the PEOPLE are starting to demand a vote on if they should stay or go. Only time will tell now how it will play out, but I'm willing to bet Grexit will be next, and the Greece will say their EU debt is null and void.