I actually do use Java. There's a data acquisition application I use called Processing that's basically an app framework for Java; I use it to read and display data from an EEG I built.
But I suspect the majority of folks who use computers have precious little use for Java, and can likely remove it from their systems with no ill effects. It's a bit like X11; the people who need it, *really* need it, but the vast majority of folks will never even know that it's there or have any occasion whatsoever to care if it's gone.
