There are legitimate reasons to not tip someone. Being a cashier typically does not necessarily obligate someone to tip you. Lots of times people will say "keep the change" at a fast food restaurant and the workers take home maybe $10 each on a busy shift, but that isn't really tipping.

If you hate legitimate "tipping culture" so much, stop making it the minimum wage earner's problem that they work for a shitty employer and start boycotting places that refuse to pay their workers a living wage.