Maybe they woke up one day and realized that the tolerance offered to neo-Nazis had been increasing steadily, and a tipping point had been reached where they could finally be themselves in public? I mean if you want to do what we (the US) did and pretend that this is all about economic and social anxiety go ahead, but you're going to learn the same lesson we did too:

Some people have never changed, only hidden, and now they're coming out. They've been trying since day one, but enough of the people who remember the bad old days are dead, and everyone needs to relearn the cyclical lesson once again. Usually it doesn't take a major war, hopefully this time won't either.