Re: how IPv6 address and parameter configuration follows the KISS principle?
Yes, ITU is probably wrong. So is IP6, we need an IP8, with security & privacy designed in.
This brings two things to mind: the ilusion of sunk cost; and the illusion that the next version will solve all the problems of the current version.
There's no doubt that IPv6 isn't perfect, but, as the implementations show it does at least work and we have worked how to have both protocols working together.
Regarding going back to the drawing board I suggest that not only would this lead to the same kind of delay that we've seen with IPv6, but also that it wouldn't get traction. IPv6 installations are already big enough to dominate the near future, ie. industry will enforce IPv6 as a de facto standard. Much better to be thinking of ways of updating the protocols in the future with less disruption.