First, it is meant to support rights issues of Italian banks to reduce the risk that in the light of the current difficult market environment such issues would fail, with potential spillover effects to other Italian banks and ultimately to the entire economy (and there has already been a case where substantial support has been provided).
You simply cannot build a comprehensive common supervisory culture if you have to apply a different set of rules in each of the 19 countries. Just think how we need to treat fit and proper assessments differently from one country to the next. Second, you need harmonised administrative practices.