Sure, that's the normal progression, but each player has their own path, and there are always outliers. And there's just no way to know who is who in the steroid era.
Willie McCovey has a very similar career profile to Frank Thomas, and I think it's safe to say he didn't use steroids.
But that wasn't my point anyway. People who want to see steroid use will see it, no matter what. Player A is extra durable - steroids!. Player B gets hurt more late in his career - steroids! Player C has a great outlier year - steroids! Player D is remarkably consistent even late in his career - steroids!
It's A and B particularly that kill me. If a guy is hurt, it's because of steroids. If a guy doesn't get hurt, it's because of steroids.
The reality is, some guys did them, some guys didn't, and we don't really know who and when. And we'll never really know. The question is what to do about it? Does it really make sense to have many of MLB's most prestigious record-holders out of the HOF? I know where I come down on that, but it's not me that counts. It's going to be up to MLB, the HOF, and hopefully the voice of the fans to make a final decision on that. There certainly seems to be a growing opposition to the writers' monopoly on the decision.