You were oh so close to actually saying something intelligent until that last little bit. 
The vast majority of them, and the German population at large for that matter, had no idea the Jews were going off to certain death. Nazi propaganda told them all the the people on the trains were being shipped off to semi-inhabitable frozen hell-holes in conquered territory to the East, much like Stalin and his forced mass exiles to Siberia in the 30s -- very tough to survive, but not certain death.
Rumors of much worse abounded both in the ghettos and German towns, but spreading them in either case was an excellent way to get a midnight visit from the Gestapo with a quick kangaroo court trial for 'Spreading defeatist propaganda' or suchlike BS followed immediately by a bullet, noose, or guillotine.