I'm really amused by the argument you've been making here and on the Cerf article. The gist of it seems to be:
(a) ISPs and businesses won't invest the time and effort to move to IPv6 because there's no demand from customers when 32-bit IPv4 works fine.
(b) If the IETF had instead enhanced IPv4 to transparently support extended addresses, we would simply need networking vendors to support it across their product lines and it would eventually be available everywhere on the Internet without any extra effort from ISPs or network administrators.
(c) All vendors would universally agree to take on the necessary manufacturing and development expense to do this, even though there was no demand from their customers for this feature. They would all discontinue their old products, even though they could, theoretically, continue to make and sell them for cheaper than the extended-addressing-compatible new products.
A good example of the failure of exactly this deployment model is TCP Explicit Congestion Notification. Even though it was standardized in 2001 and it's backward compatible with existing hardware and software, there's very little deployment of ECN in core infrastructure. Why? Because it reduces hardware performance per dollar, so without customer demand, ISPs are going to give it up to save some money.
ECN is nothing but flipping a bit and recalculating the TCP checksum! Extending the number of routed address bits would be much more invasive and silicon-intensive. There is no chance vendors would do this without dollars on the table.