I hate wasting food. Since I live alone, my kitchen is quite low-volume, although I make an effort to pick my groceries so that any waste is compostable; and this gets collected and donated to my mom, who helps neighborhoods setup composters and urban gardens.

From her I've learned that this is almost like religious prosletyzing; some people simply aren't interested in helping and can't be reached, and they'll keep dumping all their garbage into one bin because it's too much trouble for them to separate waste. Beyond the occasional reminder that I'd be happy to help them improve their infrastructure, I don't think it helps to dwell on the issue; efforts are better spent collaborating with people who are already interested.