While I enjoy each band listed, I believe one of the bigger driving forces of the 70s , perhaps only rivaled by Zeppelin, was Pink Floyd.
They owned the 70s. With their best selling records all coming out in this decade (Dark Side of the Moon, Wish You Were Here, The Wall), all I can ask is...why did they get left out?
Then again, I guess the reason they got left out is because they're too obvious perhaps.
Good list, though I may have done it differently.