... and the 'poor planning' simile fits forced IP6 adoption far better than IP4 addy assignment audit/revision across the board.
The OP is right. Many organizations have large IP4 blocks that are not justified or properly utilized. I recently encountered a city hospital (!!) in northern NJ which has a PUBLIC IP4 ip for every floor. Pretty silly and exactly what the OP is talking about. Never mind the old A, B, C type allocations that have been left alone since old post ARPA days. If an organization wants a public IP4 addy, it should get only one and manage it properly. Yes that will take some work, but far easier than IP6 implementation.
The real IP6 motivation appears to be that Big Brother wants to be able to trace all traffic directly to a specific source host, which full IP6 adoption would make possible. IP6 adoption should be resisted by the free world on that principle alone.
Furthermore, you do realize that most IP4 and IP6 stacks are usually implemented separately, right? Considering that the US gov't is evidently still having trouble securing its IP4 based hosts, imagine how it is going to do with the challenge of securing them in an IP6 environment.
Can you say - come in - we are open, wide open, i.e. "Welcome, Chinese hackers..."