That's a very good point. Considering the sorts of things that people are able to ignore (while paying attention to other, highly insignificant things) I think it's mostly about what feels good to the people doing it.

In a world in which seeming "socially responsible" and "environmentally responsible" is a status signal, people will do small things to give off that signal.... while ignoring all sorts of other areas in which the slightest awareness or outrage would lead to immediate change.