What is even the motivation for stealing a bicycle seat? How much can you hock it for?

I think I would forgive it if some poor soul had stood here after glancing around furtively to confirm that the train cops were absent, and computed: "Taking this seat will ruin the evening commute of some rich person, and likely the eight commutes after that, but he (probably he) can take it, whereas I need to sell this seat to get the money to buy the drugs to sell the drugs to get the money to buy the bread to feed my starving family—clearly a Kaldor–Hicks improvement, and after my drug-dealing startup takes off, I'll be sure to spend the occasional Monday evening replacing missing seats at a train station bike rack not unlike this one."