I see similar things in rural Thailand as I saw while traveling through Central and South America. Household waste was simply thrown out the back of the house - where it would be cleaned up by dogs, rats, birds, ants etc. The problem now is that there is so much waste that is either inedible or non-biodegradable.
Add to that- there are very few places where legal dumping can by done (in my area at least) - so all public and non-farmland is fair game to become a tip.
Nothing will change here unless there is a major public awareness campaign against littering - and alternatives are provided to the people. (As in designated rubbish collecting sites or recycling - however I have no confidence in 'real' recycling occurring in Thailand because recycling costs money).