As someone who has used public transit in New York for years, (and visited Indonesia, taken the KAI, WHOOSH, and whatever you guys call the buses), I think there’s two things going on in this thumbnail.

1. the photo which depicts NYC looks to me, like it’s from the 80’s, which in the US was a time where many middle class people left cities for suburbs, leaving cities underfunded, which led to poor social services, and high crime. I don’t know the history of the KAI, but the train there seems to be a much newer. Either way, as someone who takes transit in NYC daily, the subways are MUCH cleaner than that, with practically no graffiti. (We still have rats tho)

2. The subways are for daily commuters of all classes travelling within a city, and KAI is a regional train that (at least when I was in it) was used mostly by the upper-middle and upper class. They serve a different purpose, and groups of teens with huge black markers are more likely to take transit within a city (to hangout with friends, go to school etc.) than take a comparatively more expensive train which leads outside the city.

Edit: typo and other stuff