interesting thoughts. but i must admit i've never really been into this "you MUST listen to blues music in order to understand rock n roll." shouldn't we all listen to Bach to understand music at all ? well, many people don't.
blues music doesn't really get to me, it kinda bores me, actually. i feel like these musicians have been singing about the same themes for a hundred years and i feel like saying "ok, we get it now, you can stop".
and the 12-measure structure, even though it evolved a lot since robert johnson, well, it bores me too, i hear it too much, this structured loop.
but sometimes, once in a while, i listen to blues artists. just not too often.