CJG Now Thankfully Living In The North wrote:

But who brings the half eaten burgers, beer cans and piles of vomit?

That would be the people who avoid buying a ticket because its
unlikely they will be have much problem getting through ticket
barriers (if they are opreational)

No it bleeding isn't! Only the other day, I saw well-dressed people on
their way to the office (a) eat a banana and leave the peel on the
window shelf and (b) eat an apple while going up the escalator and, when
at the top, chuck it into a corner.

And have seen similar behaviour from a whole range of genders,
ethnicities and classes.