Regardless, I suspect if you were in train packed full of people from various socioeconomic backgrounds on a hot day, the smell of food would be the LEAST offensive scent on offer.
If there is one thing I learned from moving to the American Midwest is "to each their own." Everybody has their own palate, tastes, wants, and dreams. Nobody is "wrong" and keeping an open mind is always the best policy.
I find the smell of certain things, like old cooked broccoli or kale, to make me want to vomit. But if a passenger on the train was eating it, I don't think it would disturb me nearly as much as endless music that interrupts my concentration. I don't see how these are in the same boat, even though the music is merely annoying and the smell of putrid greens makes me want to vomit.
Constantly feeling the urge to vomit doesn't disturb your concentration, but music does?
I'm confused how you can't see the commonalities between the two examples. In both cases, a person does something which disrupts many people in a shared space.
I don't know where you got your "most people" supposition from.