Some people are not meant to be front of house. If you think you are one of these people, please don't get a front of house job. I again ran into a popular chain retailer to grab a few things. The cashier went through the entire transaction without saying one word.
It makes me angry. I don't need gushing customer service because I dropped $5 on some bottled water. But I deserve something. When you think about it though what is the employ's incentive to be nice? You can't be demoted. You are on the bottom rung. You get raises by seniority. That means the company only takes into consideration how long you have been standing there (not talking) as opposed to how well you do your job.
But still. If you have social anxiety disorder, a bad attitude, or just out and out hate "the man", take it out on the cans of soup and stock the shelves instead.