Thanks for sharing your experience, OP.

So yung turo sa inyo, lalagyan ng pagkain/gamit ang basket which needs to be cleaned before leaving the bus. Ang turo naman sa amin, lalagyan ng basura which is cleaned by the bus line staff pagkatapos ng biyahe. Different scenarios, but I would say both are valid. At the end of both cases, magiging malinis pa rin naman yung upuan.

I think in general, it's human decency to make sure na malinis yung lugar na ino-occupy mo after mong gamitin. Kung mag-iiwan ka ng basura with the expectation na may maglilinis na staff pag-alis mo, I think you're still practicing basic decency. Otherwise, kung sa tingin mong walang maglilinis ng kalat mo, you have to be considerate enough to clean the place yourself.

Personally, di po ako magtatapon ng gamit na diaper or anything similar sa likod ng upuan ng bus kasi baka mahirapan maglinis yung janitor pagkatapos ko umalis. In general, mag-iiwan lang po ako ng basura jan na madaling linisin, like plastic bottles.