Velo is overrated. It obviously makes a difference but you can get guys out various ways like movement, command, changing speeds, deception, keeping the ball on the ground, and velo is only one of those things, and you can't get guys out with just one of those, you need a combo of 2 or 3 at least, and velo doesn't have to be one of them. Nobody says "we need more pitchers who can change speeds well".
We also tend to get a lot more excited about K% than BB%, but I don't think one is more important than the other.