Here's why. I hit 100 balls the way I was swinging, and measured and noted where on the net the balls were hitting. Next, I tried hitting another 100 balls with a "forced" pronation of the lead wrist. Basically, I was putting in more lag in my swing. I was conscious of the wrist position before and after impact.
Went back after taking a little break with my son, and started hitting balls with the pronation of the lead wrist. The balls were definitely going lower by a few degrees. I hit about 20 balls with each iron 7,6,5,4,3. My reverse K was about 15 degrees, spine at almost 30 degrees.
I will see tomorrow if my distances increased and spin is reduced.