There's one thing I still don't understand in all this tipping business in the US (and maybe Canada as well?): what about the other staff members in a restaurant or on the train. Where I live you not only tip the waiter (provided the service was satisfactory) but everybody that provided a pleasant stay: waiter, bartender, kitchen staff, cleaners, etc. So what usually happens is that all tips are being collected and divided once a year among all personal. Advantage is that they all feel responsible for a satisfied customer.
There difference, IMHO, is that here in the USA, the table waitstaff (and only the waitstaff) can be paid far less than the legal minimal wage. That's because the law assumes their pay will get subsidized by tips. They are the only workers for which the law does this. In contrast, the kitchen staff, busboy/cleaner, etc, all have to be paid, at least, the legal minimal wage.
The exception, and one of the points of debate here, is that this apparently is not true for Amrak dining car waitstaff. Amtrak has chosen to not pay the dining car waitstuff less than minimum wage, but instead paid them way more than the minimum. A lot more to compensate them for the long hours, and being away from home.