I have lived in the US for nearly 20 years (originally from Europe), SF for ~10 but I've since moved to a less progressive state in order to raise my kids in a

I have lived in the US for nearly 20 years (originally from Europe), SF for ~10 but I've since moved to a less progressive state in order to raise my kids in a better environment. I don't tip, ever. I've been pestered with why questions even after I calmly and clearly explained myself, chased down the street by angry waiters, cursed at and even threatened with violence. Still, I don't tip.