Why are Rice and Dawson more deserving than Dave Parker? Parker finished top 5 in the MVP voting 5 seasons, which is better than Dawson or Rice. He also won 2 batting les and was a great fielder with a tremendous arm. He was the best player on a World Series winner 1979. Go back and compare his career to Rice and Dawson, and you'll see all 3 are about even. Parker just has a stigma because of his coke problem.
Also, Jim Rice's stats were inflated by Fenway, although he was a great hitter.
The McGwire issue is complicated and at this point kind of beaten like a dead horse. I guess they're not letting him in. I do agree in a way, but it does seem arbitrary to "wipe out" his career from the book.
Bonds is different because he was already a great player prior to becoming a roided out freak. Even if you throw out all the later seasons, he still is a HOF'er. Mcgwire was not a HOF caliber player before the roid craze.