What is with gum chewing?

Stone Harbor - What is with gum chewing? I was taught that it is rude and inappropriate to chew gum while working or at school. I go to a grocery store and the cashiers are chewing away, I go into a parish office and the secretary is chewing away and then I go to a place of business and the salesperson and manager are both chewing away! These are adults and I wish their supervisors would forbid the unappealing chewing and chomping.