I'm old enough to remember not needing to tip at starbucks or Panera, but not old enough to remember minimum wage keeping up with inflation.

The place where I first noticed the "tip your cashier" thing happening was the Panera at my university. Why in the hell would I tip someone who's job is literally to take my order, and maybe hand me a pastry? These people aren't making minimum wage either, I had some friends there and the job paid significantly more.