The league couldn’t institute a ban on smokeless tobacco, so some cities did it themselves.
There are some things that just go together. Peanut butter and jelly. Hot dogs and ketchup. Milk and cookies.
Baseball and chewing tobacco.
It’s a tradition that dates back over a century, as the rise in popularity of smokeless tobacco, colloquially referred to as dip, chaw, or chew, coincided with the widespread use of baseball gloves. Players would spit into their gloves to keep the leather moist.
Better and more hygienic ways of breaking in leather gloves have been developed since the early 1900’s, but the use of chewing tobacco is still linked with the sport of baseball for better or for worse.