Indeed, at some point the situation with IPv4 will become so grave that it will become impossible to ignore IPv6. Transitioning to something like BangIP might be much easier, but it will be impossible to force people to adopt it, which will only lead to fragmentation. IPv6 might cause massive fragmentation on the internet right now, but once the IPv6 gets closer to 100% we can start dismantling the IPv4 infrastructure, which will force the remaining few to switch to IPv6. There's no way to do that with BangIP, as it involves keeping the IPv4 infrastructure intact, which will allow people to continue browsing a large part of the web and thus there will be little to no reason for a lot of people to switch to BangIP. In the end IPv6 will be a much better solution than BangIP.