It might have been better not to create the euro in the first place, but now that it exists its “unwinding” is neither desirable nor inevitable. There is no unwinding of this system without causing a much worse mess than the one we already have. If you think things are hard right now, see what happens if the eurozone comes apart.
Willem Buiter thinks through some of the possibilities in the FT: The terrible consequences of a eurozone collapse. His thinking on a voluntary exit by Germany, as opposed to coerced exits by the fiscally stressed (a more popular scenario), is especially interesting. That would be no better, he argues.