"Interestingly enough, despite there being no relationship between higher fastball velocities and strike zone %, there is a moderate relationship between higher fastball velocities and walk rates – so another factor must be involved."
Power pitchers tend to have power breaking balls too. I bet THOSE have lower zone% and lead to the walk rates.
ANOTHER IDEA - power pitchers get more whiffs. That's less contact. Less balls in play. Deeper counts. More walks!
It's elementary, batman.
wait