IPv6 is far from perfect, but this article seems to hit on all of the wrong things. IP was meant to be flexible, and this post seems to want to remove that, potentially removing the features that allow VPNs and wireless cards to hook in to the OS easily.

Networking changes slowly, no one wants to spend millions to replace the expensive gear-- just so we can use a new layer-3 stack. No one wants to pay thousands/millions to get a software update released-- then hope it doesn't take down the network.

IPv6 was released in 1998, after 20 years-- its almost deployed. And the problem is harder today: we have more devices, more networking gear, more connected equipment. Getting IPv6's replacement as widespread as IPv6 after "only" 20 years will likely be more challenging.

Some changes proposed make sense, and we're already moving to that world. A world where multicast is the default functionality, where every IPv6 interface has a local-link address that can be used instead of MAC address, where multiple-addresses and multiple routers are standard, and perhaps a world where roaming is standard (also see SCTP)