The word "sustainable" has lost all meaning. I don't know what sustainable means anymore. I just say it to make people feel better.
Echoing Sarah, it seems that the word "sustainable" has lost its original meaning in the process of achieving totemic status in modern parlance. It's just another way of saying "good" or "acceptable", except in an obnoxiously pretentious way...
...So naturally I find myself using the word all the time. Please help me.