This is the norm in America. I would assume this is common knowledge, but even still my comments are directed towards those that admit they know the staff relies on tips, but don't tip anyway because it's "not their job".

Again, if you go to these businesses knowing the majority of the waitstaff's compensation is in the form of tips, and you patronize the business without tipping anyway, you are on the side of the employer. The employer sees zero loss in revenue from your lack of tip. You have formed an alliance with the business owner to exploit the worker.

If you would like to not screw the employee while also not tipping, the answer is simple: do not patronize that business. Contact the owner and let them know you don't plan to return until they pay their staff a living wage. Otherwise, you're just selfishly joining in the exploitation, full stop.