I can't speak on behalf of a russian soldier as I don't know any, nor was I present at the battle of Stalingrad, but, from my readings, their fight WAS for very much for mother Russia and was most definitely an issue of national pride. Common sense tells you that part of their motivations were for their families and relatives as would be with any "normal" human being.
The German's had something far more difficult in front of them to deal with than an English Channel or Atlantic Ocean, a Russian winter on vast, open steppes. It was a matter of Hitler's fanatical preoccupation with conquering Stalingrad mixed with the devote patriotism and "winter legs" of the red army that made Stalingrad the absolute blood bath it was.
However, maybe we should try to maintain the topic at hand.
1st Ranger Platoon of Canada
Rangers Lead the Way. Most of the time.