Squating on the toes or allowing your knees to go far over the toes is not bad. It is actually a really great way to work the quads.
It isn’t the movement that is bad, rather it is the body of the person that is performing the movement and how they have been living their life and what they are currently capable of doing.
It is the exact same thing people do with anything that does not work for them. They blame the movement instead of themselves. Just like presses behind the neck or chin ups behind the neck are not bad to perform, deep knee bends on the toes or allowing the knees very far forward over the toes are not bad as well.
