It's the new folks just having a wildly arrogant view of their new protocol. Ipv6 had everything and the kitchen sink thrown into it and made only token efforts at ipv4 co-existence. Plus the endless hype of ipv4 not being available. What they really meant was FREE ipv4 addresses won't be available, but between spending $5K to get a small block or re-doing your entire network to ipv6 -> plenty of people would rather pay the $5K!
The irony - despite seemingly unlimited ipv6 addresses my home internet is now a mess of randomly changing ipv6 addresses... I feel like I'm back in dynamic DNS / NAT days (ipv4 + port).
The s' and u' string prefix issue in python is an absolute embarrassment. They had a perfect / clear upgrade path that would allow stuff to still work with python 2. In their Unicode purity campaign they tried to force everyone to 3 by making it a total PIA to work with 2 still (such a similar story with ipv6).
Folks were like peace out for at least 5 years until they started bending a bit (also ascii handling for HTTP stuff got super annoying). Once they backed off it got a lot better on the transition.