So the fix is to have people changing them more often + even having more available, but that would require more work and money.. blaming foreigners are just easier
It has nothing to do with blaming foreigners, my local parks here in the US are all carry in/carry out parks with lots of signs posted stating as such, and it's not a massive problem.
I'm absolutely going to blame lazy fucks who can't hold onto a bit of trash long enough to get to a trashcan or who can't be bothered to clean up after themselves. Blaming it on lack of trash cans merely offsets responsibility and ignores that park cams are a magnet for wildlife and lead to trash blowing out of them
So the fix is to clean up your own goddamned trash and take it with you when you leave.