They can't speak from experience but to be honest, I think a lot of people would be a lot happier and bigger if they just took everyone's word for it, ignored the machines, pounded on the squat for a few years, and never sought to prove this to themselves. Sadly I can speak from experience and regret a lot of early training errors - then again back in the late 1980s the machine craze was in full force and the BBers hardly every squatted and the deadlift (along with all forms of pulling from the floor) was 'dead' for all intents and purposes (and people think deads and cleans are rare now in commercial gyms). That said, machines can certainly serve a purpose for targeted assistance work to improve weak links or imbalances, rehab, and the infirm.