I train predominately with machines.. I believe that free weights just have too many negatives in regards to plain old gravity and balance, weaker supporting muscle etc.. plus with my aweful shoulder Injuries I prefer to not have to balance the load and just put the load on the muscle.. yes, they did just fine in the golden age with free weights. It can be done with just free weights.. but its not optimal..
That being said machines are only as good as the set up.. many are not setting the machines up right in regards to their body and the pivot points etc.. I see it all the time even with video with pro competitors. But if you have a quality machine with great biomechanics you can eliminate the negatives of free weights in regards to their inherent flaw of strength curves in many movements..
My home gym is all hand picked machines that I found worked for me.. I still have dumbells etc and still do db curls, one arm rows etc.. but 90 percent of what do is Hammer strength, Watson, bodymaster, icarian, nautilus machines..