Do they honestly believe the whole internet to upgrade to a non-backwards compatible address?
The whole Internet will upgrade. IPv4 is reaching its end of useful life. End of story.
Or ISPs will just migrate us more and more behind NATs killing peering & bittorrent and making us back into consumers.
There's only so far they can go. It's estimated that Asia is going to start having new clients IPv6-only in less than a year due to their constant rapid expansion of internet.