The IETF didn't expect anybody to transition to IPv6 because it was "the right thing". They expected people to use IPv6 because of its advantages over IPv4.
What were these supposed advantages? The same advantages that drew people to the Internet originally. Unfettered end-to-end connectivity. The opportunity to participate as an equal without having to pay through the nose. The liberating concept that you could plug in anywhere without having to worry about what kind of access you get and what the tariffs look like.
Fifteen or twenty years ago, the IPv4 Internet gave people freedom from the tyranny of buying ISDN circuits or paying exorbitant fees to be a mere "terminal" on an X.25 network. Today the IPv6 Internet gives people freedom from the cruft that litters IPv4 today as a result of the scarcity of addresses and the widespread use of NAT.
As it turns out, the people who want these things have already been using IPv6 for years. We apparently account for 0.2% of the Internet's user base.
The telcos had it right to begin with. Most people just want a dumb terminal. Provider-side NAT is as good as IPv6, as long as the Youtubes still work.