In a GNU humor page they say
"Gates described MICROSOFT's long-term strategy to develop a scalable religious architecture that will support all religions through emulation."...The irony here is WINE (windows emulation layer). GNU and linux try to emulate Windows, Unix, and BSD in every way they can. GNU pretty much tries to mock all operating systems and copy them... in one unified GNU project with different variations. Then when people need access to stuff they can't use in GNU, they use emulators to gain access to other operating systems.
The GNU project tries to unify all as GNU using it's viral license that ties everything and locks everything toward GNU, whearas BSD says "this code is good, now do what you want with it". Can the GNU not see the irony when they criticize Microsoft?
"A single core religion will be offered with a choice of interfaces according to the religion desired"That's exactly what all the linux distros do... unified by a single GNU religion (GPL license) but each distro has a variation of religion (KDE vs Gnome interfaces, package managers, etc.)
That microsoft joke was from 1994 apparently, so this is probably back in the day when Linux was still fairly small and growing, and now GNU is eating its foot when the humor bites it back. What I mean by this is they could make the joke back in 1994 but now it's so ironic that the joke almost looks like a mirror staring right back at gnu.
Quotes are from:
http://www.gnu.org/fun/jokes/microsoft-church.html