You could be right for all I know. But there is a counterargument, that machines cause repetitive use injuries due to the precise movement pattern, and where the body can't adjust to suboptimal patterns by changing the movement slightly to a less injurious pattern. Charles Poliquin warned that the smith machine was dangerous. Another thing that is injurious apart from the load is the volume, lots of volume will do damage over time. Most of today's bodybuilders use lots of machines and there is the usual overuse (or otherwise) damage to shoulders and so on. Lots of injuries on machines, to quads for example. Milos has had a lot of injuries and uses a lot of machines and "pump" workouts, the quads blew on hack squat. Then you have the ones who train like an idiot, like Platz, or Liedelmeier who still go strong. For sure you guys have a point that lighter weights and careful lifting should be less injurious but there's a lot of factors involved, is what I'm suggesting (even genes- huge factor actually). O'Hearn seems to be going strong despite training really "heavy" with many free weight movements. A personal observation, hugely biased I know, is how people who avoided "heavy" deadlifts seem to be tweaking their backs more often on bent over back movements or leg presses or what have you. I think it's because the back is relatively weak and can't withstand stress as well. I have damage from deads but we are talking about 30 yesrs almost of maxing.
Joswift makes a good pount about stretching muscles for growth during training,as that's what the current research seems to show. Lifting in the lengthened range hypertrophies a muscle more than training in the shortened position. For example, one study showed training the calf in the first half of the movement, the stretched bottom position grew the calves more than training in the upper half. Traps grow from just deadlifts and there is minimal movement, just stretching and contracting in that stretched position. I know most of you heard about this a thousand times, but in case someone wasn't aware 
But then you have the monsters who only did short range movements, Jason Huh was an example, if you're curious, look at some clips 
Heavy deadlifts only work the erectors in a dynamic tension/isometric fashion
The back is straight and doesnt change from the start to the finish of the movement
The only way the erectors work through a full range of motion is if you deadlift with a arched back like a cat, and thats not really a good idea
