Why don't cordless phones have a global phone book?

I want to get a new 4-handset cordless phone, ideally 5.8GHz, but as far as I can tell, none of them have a global phone book.

They all store the phone books in the handsets, and most give you a way of copying between handsets, but none just store it in the base-station for all handsets to use.

One I found (AT&T I think) that actually has a base-station stored phone book, but it only works when using the base station!

Anyone know of a multi-handset system (even 2.4GHz) with a global frigging phone book? Why is this such a bizarre requirement? Am I the only person who wants this as a feature?