I mean... yes. And then there's the real world where your parent company has bought a dozen small companies over the years who have things spread across all of the 1918 ranges and you're setting up VPNs and static NAT and RIP and IS-IS paths and... you just do something easier. It's not a _good_ idea, but it's definitely a thing that happens (fortunately, for me at least, it's been a good long time since I've had to deal with that brand of network badness).