I don't think it has to be bad for anyone, although that's assuming that politicians were of the disposition of accommodating policies and practical solutions.

There is a great discussion about the history from inception, problems with and current state of the EU. Can't say I know as much about the flaws in policies that were discussed in that but seems to me, for all of the benefits of EEC, the problems the Euro and the Brussels apparatchiki imposes outweigh.