I can only recommened the opposite: if you are doing strength training by all means use mostly barbells and stick to the big 3 (some sort of press, a squat and a deadlift variations). I hurt my back, shoulder and knees doing various machines and dumbbell variations over the last 15 years, the fear in regards to lifting heavy with barbells usually stems from horrible technique, most people do not realize that lifting is a sport that needs to be learned, it's not enough to just "push the weight".