Clearly, that waitperson had a complete misunderstanding of the whole relationship of service quality and tips, and did not understand much about cause and effect, either.
Poor service quality should not bear a direct relationship to dollars collected. I'm sure that you can think of an instance when you received good, personable service in a deep discount store, or from someone who was giving something away for free.
"I can't afford to give good service here" is a very lame excuse. Attitude and focus do not cost money.
As a business person, you are responsible for the results of your business. (Duh.) If you are not conveying the proper sense of cause and effect, you need to rethink your focus.
Money follows service.
Are you getting "lousy" tips?