In theory employers are supposed to make up the difference if tips don't meet minimum wage. But it's infamous for being poorly enforced.

I agree that is a problem. I suspect it's receding as the percentage of restaurant sales paid by credit card increase.

People who dine at restaurants that likely commit wage theft might tip for moral reasons, but to me, it makes more sense to boycott those restaurants and communicate to managers and owners the reason why.

They can, yes. But the instability of wages is a bigger issue. You can do amazing one day, and horrible the next. Combined with the fact that we teach next to nothing about financial planning in the US, and the extreme reliance on consumer debt by our economy, tipped workers are more like gamblers.

I agree. I would love to see tipping be replaced with a steady wage or salary based on skill, seniority, etc., like most careers have.