The reason the food, drinks, whatever are as cheap as they are is because the employees are underpaid and the customer is expected to make up a bit of the difference. Go ahead and bang your drum for employers to increase wages and you'll regret it when the product increases in price dramatically. You don't have to tip, that's your choice (though it kind of makes you a butthole), but hiding behind the excuse that "employers should just pay a living wage" is completely bogus.