In a Fanshot at RoyalsReview, some asked to have explained what is wrong with his swing. I created a few .gifs of a typical swing of his and here are the problems:
Full swing for reference
He has a small hitch (dropping of the hands). Ignore the drop from the knees, instead his hand placement.This may or may not be a problem. It can lead to downward momentum and dropping the back shoulder
And he drops is back elbow quite a bit. Once the elbow/shoulder drops, the only way to hit a ball with power is to sky it. One way to see what I mean is to do it yourself. Stand as if you are going to hit a ball and have your back shoulder/elbow down and swing. The only option is to pop it up.