Essentially, it seems that cork quality has been going down for some time, leading to variability in quality of wine and also leading to a certain small % of wine being lost each year due to spoiling caused by bad corks. Hence this recent move towards aluminum caps. However...while I thought this would be a nice narrative that would jive with my anti-elitist (or maybe just anti-French) opinions on this issue, there is a whole sustainable development angle to this as well:
Today, the survival of cultivated cork forests, many of which are on private land, depends on their worth. If nobody is buying cork, landowners will use the farmland for something else. Enter the conservationists. As wineries began ramping up experimentation with new closures, WWF launched a program in 2004 encouraging consumers to "choose cork" to protect the forests, the biodiversity they support and the thousands of rural jobs they create.What I like about reading about this program, however, is that it is finally consumer-centric, market-oriented conservationism, rather than regulatory tightening. Check it out.