There are many things you could say about social democracy and Social Democratic Parties in the 21st century, and what exactly they mean in a post industrial West and post communist east. But unelectable is a big word that you can in no way justify.
Yes, one of the fascinating things about politics now is that the old socialist tradition and heritage is alive, but the more radical and utopian elements are variously dead and dying. Which does not mean that there are not socialists under eighty who have radical and/or utopian politics, but that this radicalism comes from other sources.