Did you check a workstation manual about how to configure an IP
address for your machine? Last time I checked, the ones I looked at
claimed that you should get an officially assigned network number.
That's it. Now, explain the difference to them poor users. It would be
better if the manuals would say "if you need an official number, get
one. If not, use xyz." If xyz is well documented as a reusable number,
then there should be a defensible situation not to route it later.