A big reason is mergers (something HP has a lot of experience with); merging two 10/8 networks is a mess but if they have unique IPs it's easier.
Also, I think the concept of a "private network" is inflexible and in some sense a premature optimization. If you use unique IPs you can decide on a subnet or even host basis what is exposed to the Internet and what isn't.
Also, I think the concept of a "private network" is inflexible and in some sense a premature optimization. If you use unique IPs you can decide on a subnet or even host basis what is exposed to the Internet and what isn't.