This is very interesting, good points. They don't really say what lead to this. EU and US were neck and neck in GDP growth department until GFC. And it's really not obvious what changed.
I'm not going to outright state it, but here's where you should start: there's a communist holding the position of chairman of Goldman Sachs International (yes, really, I know how it sounds. It's still true). This person made a BIG change to the Euro during the GFC ... and what you're asking was exactly the expected result.
And let's not discuss the recent changes.