Adding a powerful single regulator to a powerful and independent central bank would create an entity with significant authority outside the day-to-day direct purview of government, so governments have opted to combine the regulators and strip the supervisory and regulatory power from the central bank. But please note that they have continued to make their central banks responsible for financial stability.
Saying that, I certainly do not wish to ignore the fact that the past few years have been difficult for many people and that challenges still lie ahead of us today. Even though Germany did not bear the brunt of the euro crisis, it has nevertheless clearly left its mark here, too.