This post suffers from lack of a clear example. You give no reason why not tipping should be preferable in spite of the moral revulsion. If you wanted to make utilitarian claims like Yvain pointed out, it would be one thing, but it's not clear at all that you are filling the moral void created by not tipping with anything better. A better argument would be: think about what you really value, and if the sum total of 20% of your food budget isn't worth avoiding the feeling of moral revulsion you get from not-tipping, then don't do it. This statement doesn't suggest that one shouldn't feel moral revulsion, just that we should consider the price. If you want to argue that we shouldn't feel moral-revulsion to not tipping, then you need to provide arguments as to why it's better for the world not to tip. I think there is a good point lurking in this post, but it's not explicit and the post gives no real advice about how to identify, evaluate, and deal with 'moral junk food'.