Schilling tried to stop once before and went through many of the typical withdrawal symptoms, becoming violently ill. You have to wonder why someone would start chewing in the first place. Reds catcher Brook Fordyce, who doesn't chew, nearly fell prey to the same pressure. One day as a kid his brother let him try some, but didn't tell him he wasn't supposed to actually chew the tobacco like gum. Fordyce believes that guys start because baseball can be a nerve-wracking and sometimes boring game.
Nobody chews seeds because they're hungry.
I don't think it's pressure, but somebody tries tobacco because they see someone do it at the big league level. Baseball has banned smokeless tobacco in the minor leagues and fines players if they're caught. But no such ban exists in the major leagues, and none is likely to as long as the players' association has so much control. It's legal if you're 18 years old. Fordyce believes it's about education, which would be a start.