Grandpa Joe was an asshole. In both versions of the tale, it is very clear who is number one in Grandpa Joe’s mind. He decides he must accompany Charlie to the chocolate factory. In the movie, he actually speaks of the ticket as though he, not Charlie, was the winner.”I’ve got a golden ticket.”
He considers eating everything a viable option. He doesn’t pause to consider that others might be hungry. He puts his immediate desire for fizzy lifting drinks ahead of Charlie’s lifetime supply of chocolate, and convinces Charlie to break the rules and drink the fizzy lifting drink!
In the very beginning, Grandpa Joe lays comfortably in a bed with his wife and the elders of the family instead of helping the family financially or domestically at home. He sees his daughter working long hours in a run down laundry house, and poor Charlie delivering newspapers to help his mother make ends meet. The only motivation for this jackass to get out of bed is to go to a chocolate factory. As far as he is concerned a loaf of bread is a banquet and he has every right to smoke tobacco from his pipe while the family starves…
Finally the final point that demonstrates what a evil man this senior citizen really is, is this: When Willy Wonka yells at Charlie and tells him that he gets nothing, due to the fact that he stole fizzy lifting drinks, Grandpa Joe’s immediate reaction is to avoid an apology, and try to convince Charlie to sell the everlasting gobbstopper to Mr. Sluggworth . Good thing that Charlie did not listen to his irresponsible grandfather and decides to return the gobbstopper instead. This is an awful man people.