That is a good point, if you consider XSD then that is an XML connection, it starts to become a bit complicated and I see why people start to dislike it. I forget about that because to me it’s just about the idea of a graph, which is otherwise quite elegant. Why not have a graph type-free with just string literals; much richer information about what kind of values go where can be provided through constraints, vocabularies, etc.

My favourite serialisation has got to be dumb triples (maybe quads). I don’t think writing graphs by hand is the future. However, when it comes to that, Turtle’s great.