There's economic research that shows it's more efficient to regulate (in some sense, "blame") the lenders, because borrowers are often desperate. When you're desperate, you have reduced capacity to objectively judge the consequences of borrowing and are also less sensitive to "blaming", potential penalties for overborrowing, etc.
From this perspective, putting all the blame on borrowers while exonerating the banks is exactly the opposite of what we should be doing as a society, if we want to avoid another debt bubble.
I'd fully agree with you if we were talking about small entities. Maybe we can not expect every citizen to fully learn the details and pitfalls of all those financial constructs available and thus want to protect them with regulation. But when we are talking about nation-states... whom else can we expect that kind of due diligence from to make properly informed decisions and understand the consequences if not governments of nations, representing millions of people?
Lets imagine some democracy votes an incompetent fool into their highest office, who starts making "bad deals". Would you expect other countries to not agree to those deals for reasons other than their own interests?
