Is it less offensive if, when littering, you try to do it in a slightly more organized way?
True, you are leaving a mess for someone else to clean up, or for the environment to slowly process over the course of centuries. However, if someone does come along to clean up, this would be easier to collect and toss in a bin than the same bottles scattered on the ground.
When looking at bottles and cans being littered, it strikes me that this is a relatively unique case where so many people blatantly flaunt the law AND leave their DNA on the evidence.
One would think if there is that much a demand for a trash can, the powers that be might consider putting one in the area. If they are neatly collecting the trash, they would likely use the trash can. Just a thought.