I've been living in North Thailand for almost 3 years now and littering is still weird here for me. You'd go to the this pristine clean temple where everyone is barefeet and it's so cosy welcoming there then you go back to the parking lot that has a mountain of trash just rolling down hill.

The tourist blame is a bit silly too as foreigners are often charged 10 times the price for entering national parks (1$ for thai, 10$ for a foreigner) to the point where whole #2pricethailand movement started. For this entry fee a whole platoon of park maintainers could be hired but I've never seen more than 3 people present even in big parks and the trash cans are often missing or badly maintained, so it seems money is definitely being pocketed at some stage.

Generally tourists that go to these parks are quite tidy here and this headline seems like a click-bait.