While true, I would add that a big reason is that freight is prioritised by rail companies, causing large and frequent delays for passengers. Amtrak owns some of its own rail, mostly in the northeast, which is perhaps less-than-coincidentally the part of the US that has the most people taking trains.
Autism affects how senses are processed, and taste is a sense - some autistic people don’t want things that are strong or that vary a lot, preferring consistency instead.
With that being said, it’s not a universal thing, different people are affected differently.