I think it is success, to be honest. I think social democracy by and large has given in to its own success. Established welfare states have achieved most of their original program. Pretty similarly, the neo-liberals pretty much established ideological hegemony where everyone accepted the market, as does the Europeanist. Once you have success and pretty much everyone is on board—or at least act as if they're on board—you don't discuss it anymore. You don't really argue about why this is fundamentally good. You start to talk about details.
That's fine when things go well, but if you have a great recession and then you have a so-called refugee crisis, you have to come up with a bit more than tweaks here and tweaks there. Because of success, we have kind of lost our fundamental ideological debate.