I have wondered what proportion of Amtrak passengers actually make considerably less than Amtrak OBS crew on an average, and what if any, is their obligation to make Amtrak OBS crew's income even higher by digging into their already smaller kitty of dollars. I know there is a contingent on AU who mindlessly keep peddling the mantra of tip, tip, tip. But there needs to be some rhyme or reason to justify trying to essentially shame people into tipping, even in face of mediocre service, those who possibly already make more than them.
If superior service is provided and one feels grateful enough for same to wish to tip, that is great. But tipping at the end of the day is an individual decision and not a requirement.