That's actually intentional. Your players are rolling a 2d6 to determine their mutations, making it impossible to roll a 1.
However, one flaw I did notice with the Town Meeting "location ban" roll is that there are 12 locations listed, and as I just mentioned you can't roll a 1. I'm guessing you can't get banned from the Town Hall, otherwise you'd never have the chance of being banned from the Apothecary if it represents 1.