Balance is everything in hitting. You may think it looked like he was off balance but the majority of time he was not. You can not hit balls with authority without balance and rhythm. As Frank aged and became less athletic, he got lower to the ground to help maintain the force and balance on his front side. He couldnt stand tall and shift on stride because he wasnt athletic enough to do that and maintain balance like when he was young.
You wouldn't teach it because it's uncomfortable and unnatural to many. But to those who are good at it, it allows you to attack balls way out in front while fighting those off that get deep enough. Ichiro was also a front foot hitter - the amazing hands thing pretty obvious there too.