Well, it's complicated.
More than so many other kinds of music, jazz takes its tradition seriously. There's about 100 years' worth, and most of it has been passed down in sound: by playing with, listening to and studying with the masters. So it makes sense that jazz musicians feel such visceral connections to their ancestors, whether spiritual, intellectual, educational, inspirational, aspirational or even just marketable.
Hence, there are a lot of jazz albums and concerts where a younger musician plays the compositions of an older, or deceased titan. Plenty of them are already out in 2011 alone: I spoke with All Things Considered weekend host Guy Raz about some of the tribute albums I've been spinning lately. None of them require that you know anything about the original composers — but they all make you want to.