"When you can communicate with the rest of the internet without an IPv4 address."
Working on it right now. There's an IPv4 compatibility space within the IPv6 space.
"Dual-stack HAS NO VALUE. It doesn't save IPv4 addresses."
It's not meant to. It's meant to transition IPv4 into IPv6. Sorta like a ladder so you don't have to climb the sheer cliff with your bare hands.
"What's needed? A complete redesign with forward and backward compatibility between IPv4 and IPv7."
Which is a non-starter. You can't make IPv4 forward-compatible with anything BUT IPv4 because of the hard 32-bit address limit. And no extension to IPv4 will work because older devices won't grok it; they STILL won't be able to see the new addresses, meaning they're STILL left out. You're asking us to cram a baker's dozen in an egg carton (128 bits in a system that can only grok 32). It'd be like trying to perceive a tesseract (a FOUR-dimensional object) in only three dimensions: something WILL get lost along the way. Which means as more sites got IPv6 (and by that I mean IPv6-ONLY--ask Asia), IPv4 devices won't be able to see them without a proxy, which has its own issues. And trying for a sharp break is like trying to go cold turkey on a hard drug: too much risk of withdrawal complications.
As the article says, get over it. The ONLY way to get more than 4 billion devices on the Internet is with something OTHER than IPv4, and since IPv4 can ONLY understand IPv4 (AND its 4 billion device limit), that means we either do it the way we are now or we break the Internet trying something else.