It's also corporate culture to blame the customers for the littering. Tim Hortons produces a disposable cup, and people are simply returning it to those responsible for creating it.

Apparently Coca Cola is one of the biggest plastic polluter in the world and they lobby against deposit return systems because it's cheaper for them to pass the responsibility to the consumers. If some countries are choking with littered plastic bottles, maybe the consumers are dropping them everywhere. But maybe the ones producing the bottles could also be seen as being responsible for not taking them back.