Having read a non-trivial amount of postmodernist work, the generator is pretty funny at first, but isn't actually all that good at creating convincing post-modernist text. There's no there there.

I don't think it's a good simulator of the actual content, but it does capture enough of a particular kind of writing style to be funny. For whatever reason, people in this area really do seem to over-use a lot of the grammatical constructions that it parodies. Maybe it'll have some positive benefit if it convinces people to avoid those constructions, now that they've been sort of called out as cliche.