A few studies have shown that the parallel squat is king for maximizing work and overloading on the muscles . High reps with low to moderate weight gives exercisers the least effective way to overload the lower body muscles. The deep squat can contribute to tight knee joints / kneecap pressure . With this in mind , would you put deep squats in your personal leg workout ?
I think it is so very important that fitness professionals understand the biomechanics of the knee joint as well as the arthrokinematics of the knee joint. How the femur rotates on the tibia and how the tibia rotates on the femur and what joints and joint structures are involved in a deep squat.
I believe if more fitness professionals were aware of the above, they would not include deep squat in their programs unless it specific to their sport. If it is not, it just not worth the risk of damage to connective tissue.
Thanks for your question.