Why did GNU choose UNIX?

Or rather, why did rms et al dislike UNIX? It seems to come up a lot that they basically settled for a UNIX clone since it was widespread. They certainly didn't care for the philosophy.

>>22,24
Don't talk bad about the *LISP* machine. It was ahead of its time. The evil here was RMS's GNU, not *nix or *LISP*. Citations if needed:
http://www.loper-os.org/?p=932
https://docs.google.com/uc?export=download&confirm=no_antivirus&id=0Bw4Wz8Ir0pl1cmNRaHYwdU1wdXM