well, its not without issues. the actual motivation was not that dhcp is the suxxors, but to promote a model where the assigned prefix was free and highly dynamic.

the goal being to support a model where one could support multiple prefixes to handle the common case of multiple internet connections. more importantly to allow providers to shuffle the address space around without having to coordinate with the end organization. this was perceived to be necessary to prevent the v6 address space from accruing segmentation.