Thats my whole point of the article...that there really shouldnt be any "primary" exercises...they are all just a emans to and end...tools of the trade that should be as customized and taylored to peoples physiques...
The primary exercise were developed in the 1800's, and based on what they knew and what they had to work with at the time...
I should have said "optimal" rather then "primary."
You are correct in that there is no right or wrong answer in exercise selection, but there are always questions of what is or is not optimal, and most of the time what is optimal, is also what is the most difficult, or painfull.
You didn't build the foundation of your physique on Hammer, or any other type of machine, you built it on barbells, and dumbells,....I'm sure it was only when you achevied most of your size, that you started going that route...
Also.. . As Van B pointed out...repetitive stress injuries are much more likely with a fixed plane of movement that is to be found in machine, as opposed to a Dumbell where you can allow a much more natural range of motion.... Of course this is assuming that the person executing the exercise is using good form, and not using too much weight...
The injuries that we see from Bodybuilders have less to do with free weights, and have more to do with them using stupid amounts of weight that they were not meant to handle in the first place...Steroids have a cortisone like effect on the body, and when you reduce inflammation, you run the risk of masking "good" pain that would otherwise tell you to back off...
You never see natural lifters getting pec tears or other similar injuries.