Do you think the general public knows what those numbers mean? I can't tell you how many times people have asked me "How much is a gigabyte?" Most people who aren't familiar with the ins and outs of technology have trouble quantifying things. I think that's why people still measure Gigbytes in "Songs".
But I digress. You can tell the general public "8Mb/s" all day long and they'll still wonder why their download speed is only "1MB/s", and believe that they're being cheated out of the other 7.