I have heard this opinion echoed by Indians, the combination of both the outside not being their problem, and thinking someone else (lower caste) will take care of it.
Its plain old apathy and no sense of responsibility or shared ownership. Outside is just something you share with other 1.4 billion people of the country.
The cycle usually goes like one idiot starts throwing trash, other idiots start adding their trash too, few weeks/months govt workers do a bare minimum job of clean-up, repeat.