You're still missing my point. Their numbers aren't that far apart up to their age 27 seasons. Both had multiple MVP's and were into the 300's in home runs. Their slash lines weren't that far apart either. Bonds' numbers were a littler better, but they were nowhere close to being far enough apart where any rational person would think that Bonds would end up hitting almost 400 more home runs than Murphy.
Murphy fell off a cliff a couple of years later, while Bonds went on to hit 400 more homes after his prime (i.e. he hit most of his home runs after his prime years) thanks to steroid use. If Murphy had started juicing when Bonds did, who knows what his stats would have ended up being, and who knows how long Bonds would have been productive if he hadn't. One thing is not debatable though: he wouldn't have put up better numbers at ages 35-39 than Babe Ruth, the greatest player of all time, did in his prime. He basically had the greatest 5-year stretch in the history of baseball for any player (including his own numbers earlier in his career and Ted Williams, Babe Ruth, Willie Mays, Hank Aaron, etc. in their primes), and he did it when most players are in sharp decline.
That in a nutshell is my problem with voting in the known steroid users. They were able to play longer at a high level due to PEDs. Meanwhile, players like Murphy and McGriff probably didn't use, their careers were a lot shorter, and their numbers don't look anything like the ones who did use steroids.