This comes up every few years. I remember there was even a link about it, but I can't remember what to search for :)
Naive approaches all assume that there is some incremental step, and IETF was just too idealistic to go with a completely new second system. But as others mentioned, it's a coordination problem. Since IPv4 does not have any signaling mechanism for upgrade, or for somehow encapsulating variable/longer length addresses ... adding that is the minimal change size.
Of course if your argument is that the RFCs and the whole v6 world is just a big unfriendly abstract wall of text, not "accidental IT guy" friendly, then of course you are right. But that can be remediated by writing better docs, providing better UX via better tools. (All the usual linux tools are horribly user hostile, and then they have an additional stinking pile of v6 tools, or the occasional -6 parameter.... but that's not exactly the IETF's fault.)
Naive approaches all assume that there is some incremental step, and IETF was just too idealistic to go with a completely new second system. But as others mentioned, it's a coordination problem. Since IPv4 does not have any signaling mechanism for upgrade, or for somehow encapsulating variable/longer length addresses ... adding that is the minimal change size.
Of course if your argument is that the RFCs and the whole v6 world is just a big unfriendly abstract wall of text, not "accidental IT guy" friendly, then of course you are right. But that can be remediated by writing better docs, providing better UX via better tools. (All the usual linux tools are horribly user hostile, and then they have an additional stinking pile of v6 tools, or the occasional -6 parameter.... but that's not exactly the IETF's fault.)