I have several friends who are squat fans. I don't know but it seems like we already use them so much it seems like it's asking a lot to do the extra work that the squats add. They all seem to have knee issues, too.
It seems the exercise would strengthen the knee but what it tends to do is just give issue. It would be fun to do research on it and see if my small group observation relates across a large sampling.
Have you noticed runners usually have hip, back and knee issues, also? It's why I quit running. My right hip was really bothering me, as was my back.