Written by Reed Hubbard and submitted on November 18, 2004
You neglected one of Joe's more sinister flaws...his addiction. In the movie, when Charlie brings home the loaf of bread, he tells Grandpa Joe that, From now on, I'M buying your tobacco."
Of course we can ascertain that Joe is hooked on drugs, likely nicotine (It's only one pipe a day, his daughter says). His habit is such that he is willing to siphon funds from a family that can barely afford to eat cabbage water.
But there is possibly another explanation. When Charlie announces that he will be purchasing Joe's tobacco in the future, Joe (in an act of faux magnanimity) announces that he is, giving it up, because of the poor state of the Bucket household's finances. On the surface, this may seem an act of self-denial, but notice that Joe seems startled by Charlie's announcement, and immediately hems and haws an excuse as to why Charlie shouldn't buy the tobacco. Could it be that Joe wasn't actually smoking tobacco, but something a bit more potent?
It's doubtful that Joe was trying to spare Charlie from exposure to reefer. More likely he was trying to save his own hide from being nailed.