Awful adoption rate? https://www.google.com/intl/en/ipv6/statistics.html

It's sitting just shy of 45%, based on what Google sees, and growing at a steady pace. The main issue is not technical, it's need. Right now, everything is accessible over IPv4, and probably over IPv6. There's no negative consequences from not having IPv4, it really needs initiatives like this one, and the US federal government one to drive things forwards (US federal agencies have to be single-stack IPv6 within a couple of years, which is forcing every government dealing vendor to get their act together on IPv6)