[Dylan16807]

> when one piece manipulates global state in a way with which another piece can't cope

This problem is the same with both static and dynamic linking.

And lisp too!

> UNIX breaks down quickly without multiple fake single address spaces for each program.

Citation needed. I don't think my programs very commonly try to go completely outside their address space. The closest thing I see is null pointer crashes, which are still not very common, and those would work the same way in a shared address space.

Edit: Yes, fork doesn't work the same. That's a very narrow use case on the vast majority of machines.