Great point about older artists. I love rock for instance, lots of 60s and 70s shyt. Kids today still respect Zeppelin, the Beatles, Hendrix, etc. Go on youtube and you'll see endless videos of white kids playing guitar tabs from old songs too.
Yet with rap Rakim gets no love today. You don't see teenagers going through a "retro" rap phase like you see teenagers go through retro rock phases. Rock stars today love showing love to older cats, bringing them on stage, doing side projects, etc. Think about Them Crooked Vultures, which was two of the big "modern" rock stars getting the former bassist of Led Zeppelin to do an album with them. Yet today you aren't gonna see some hot producer do an EP with Rakim or KRS One for instance.
I'm a proponent of the idea that if you build it, people will come. If you make a retro rap and r&b station, I bet you people would listen.