DJB was not arguing that IPv6 would never happen. He was arguing that there are some significant barriers that need to be overcome before meaningful adoption will occur.

I'd argue that many, if not all of the issues with v6 back in 2002 have been resolved, and that v6 adoption is accelerating, both on eyeball networks as well as on public-facing internet services.

Daniel is a smart guy, but this particular post doesn't really come off as being super coherent... I don't know if it's because of how far IPv6 has come and things are competly different now, making his concerns solved problems, or if he just didn't really grasp everything about IPv6 then (the examples of IPv6 addresses look nothing like actual addresses, and he seems to not have heard of dual stack...). I'd guess it's a bit of both.