Did the gym circuit help or hinder?

A number of years ago I was a keen gym freak. For quite a few years I got up in the morning four or five times a week and went to workout for an hour in the gym.  At first I met a friend there and that sense of accountability kept me going. In time my sons joined me before school so that also kept me going on a regular basis. There I enjoyed doing the gym circuit. I could go in, warm up, run through the circuit twice, warm down, shower, get the kids to school and me to the office by 9 a.m. The circuit consisted of alternating a minute each (I think) on a weights machine, then an aerobic machine. I loved it, I could do it without thinking and rip into it without getting bored of one exercise only. The first machine was a butterfly weights machine to strengthen your pecks. You sat on it, set your weight and did repetitions until a light changed. You leapt off that and onto aerobic machine, a grinder and you ground away energetically for a minute.  There were about 20 stations. Some of the weights machines included the butterfly peck machine, leg extension machine, a back extension, lateral pull downs, shoulder presses, seated leg press machine and there were others. As I say at least four days, most often five days a week twice around this circuit was my routine for several years. My muscles twitched and ached. I sweated profusely and went through towels and gym gear regularly.  I was so pleased with myself, I could out perform younger gym goers.  I could see them trying to keep up and often getting half way around and giving up, competitive twit that I was.  I do recall, though, doing leg extensions at various times and thinking, "What an unnatural movement this is! I can think of no situation where my legs would have to work this way." The same with the back extensions. The lateral pull downs just felt awkward and there were other machines I felt forced an unnatural movement out of me.  It was, however, a great start to my day and I expected the gym trainers to know what was right. I felt so righteous and superior, I was doing my body good, while others were lazy! ..... But....
I read an article the other day on the internet (so it must be true) which was entitled "Weight machines to avoid".  It listed off nearly every weight machine in that circuit and told of horrible damage they were doing to your joints, your spine, your ligaments and muscle structure! These days, when my knees start "going out" and my spine and shoulders get stabs of pain from time to time, I wonder if my blissful, righteous morning workouts actually damaged my body?