This comment gets repeated quite often and it mostly comes from people with no direct experience from it, they just say what they have heard.
While it is not good for the transmission to be operated without the linkage attached and functioning properly, it is not always a death sentence. Several factors come into play.
I've bought cars that were driven for awhile with the linkage missing or broken. I've had it fall off while driving and fixed it later. What really kills automatic transmissions is excessive heat and heavy loads when the linkage is disconnected. If one were to drive easy in a light car, you could put a LOT of miles on it before you'd see damage.
I wouldn't temp fate though. I'm not dismissing the warning entirely, just stating that those that claim destroy in short order are often exaggerating and not being sccurate.
