I am not assuming a non-leather saddle is going to be tossed. For the record I use a synthetic saddle myself. Had it for 5 years on the one bike and another 10 years. If people are tossing brooks or other expensive (by expensive I mean, uses a lot of natural resources / causes pollution) items quickly then they are the problem you should be targeting not the leather industry.

My grandmother was talking about the throw away culture shift that happened to them when bleach and other house hold chemicals stopped coming in glass jars but instead plastic. She said they boycotted every company that did that until there were no more places to get glass bottles for those products anymore. I never really thought of my grandparents as people who were into that sort of thing. It got me thinking and really spun my perspective some. I now believe it's not the industries we need to change. Corporations are always going to make the product people want, if Company X stops making bad for the environment widgets, then Company Y will start up and corner the market. It is the market that needs to change.

You want to get rid of throw-away culture? Educate the people first. The industries will follow.