While I agree that a compound movement with free weights against gravity must recruit more muscles (and in a more balanced way) than a forced path on an isolation machine, I cannot understand certain extremes like the hatred towards the lat pulldown machine, an object so easily found in nearly every gym and so easy to use.
A small internet search shows literally hundreds of variations of the same question: "I cannot do pullups, what should I do?" because it is a very usual situation many of us face. And, while I understand that the lat pulldown machine is not the same exact thing as a pullup, I think the similarity is striking, and I really cannot believe that someone who achieves a decent mark in the pulldown machine is unable to do pullups:
Moreover, the bar hangs from a cable in the pulldown machine, so that the path it follows in space during the repetitions is quite unconstrained, very similar to a free weight unlike other machines. And you can build up very gradually by increasing the load in very small steps from nearly zero resistance.
Instead, people give all sort of weird recommendations: negative pullups (dangerously taxing on the grip, joints and tendons in general of untrained and probably overweight novices), band-assisted pullups (where resistance is difficult to adjust and impossible to tune finely), surrogate exercises like the inverted row (the method I am using, but I hold some doubts because it is obviously not the same pulling direction) and so on.
Is there a reasonable and objective reason to avoid the lat pulldown machine? (besides simply "it is not the same thing"). I expect either an answer related to something real that can be understood (directions of forces, names of muscles, I don't know) or perhaps some reference to a scholar paper where two groups of training athletes were compared.