My understanding was that most of the team focus has shifted over to the filecoin project in the last year or two, and they aren't dedicating as many resources to ipfs. That said, I agree that this is pretty deplorable.
We're still paying down years of documentation debt but there has been quite a bit of progress:
* Expanded https://docs.ipfs.io/ with a concepts section. * Tutorials https://proto.school/#/ * A ton of work on libp2p specs (https://github.com/libp2p/specs/commits/master) along with a full time documentation writer.