"So-called socialist" parties in Europe are actually all in favour of 'sound finance' and of 'austerity later'. They are fully wedded to the Eurozone institutional structure as it is now and see no need to reform it. And, in the case of Greece, evidently their local allies are Pasok, Kinima and maybe To Potami so purely out of tribal allegiance Syriza is not one of them.

The Social Democrats also have a superiority complex relative to those to the left of them (the "lyrical left", "traditional left", "romantic left"...). They see them as idealists who just need to grow up and learn more about politics.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman