They weren't, they actually had more rifles in 1941 then they had in 1914 for their army. The idea of them not getting weapons is a myth propagated by films and then, as it was accepted as popular history, found its way into text books (much like the famed "Myth of Polish cavalry charging German tanks"). Its still not correct. The actual problem for the russians in Stalingrad was a lack of men, not rifles. Some divisions had been reduced to just a few dozen men a piece.
I find that odd, considering World War II movies about the Eastern Front were made after textbooks about it. I could be wrong, as I don't know many movies about the subject. My book was from the 90's or so, so I could see that it may be full of misinformation.
My apologies, I'd assumed that Western education hadn't sunk so low.
From what I've heard, the whole "one man gets rifle, other man follows him" did happen, but only once and for a very short period of time around the beginning of the Battle of Stalingrad. And it wasn't because they were cruel, callous, or lacked weapons in general, it was because the Germans just bombed a supply train. As soon as that problem was fixed everyone had weapons again. At least that is what I have heard.