As far as #21 goes. That's only because it still sells. Why is that, because people are selling to problem number #1. So my advice to you is. Buy more CD's be more media and music literate. I'm old enough to want to blame 'the kids today' but young enough to realise this is the biggest cop out of every generation. We live longer and are healthier than any generation thus far, lets take it back to these punks!
As far as #5 goes. There is a huge movement in elecronic music, and it's FAR more complicated than most know. I'm a metal head who loves Metallica, System of a Down, and above all Tool just to name a very few. I love and respect Van Halen, Def Lepard, Slayer, AC/DC and most of all The Led Zep. But seriously there is much coming out of electronic music nowadays, and it is varied and complex. Even Maynard seems to be embracing it with his remix efforts. It's the natural progression. If there was no evolution, we'd still be stuck with Buddy Holly. While he has his place, how much spin do you give him?
Oh yeah, and #7 will always kill it. I can think of a couple more recent examples.