I spent my whole coaching life, both of teams and my own kids, parroting "ground balls and line drives are hits, fly balls are outs" which I learned from the best baseball guy I knew from my formative baseball years (mid 70s). I'm not disagreeing that stats are suggesting a new way, but it's sure hard for me to overcome my bias, especially when our leadoff guy who runs a 6.6 60 has been 0-10 so far this year because he's lofted every damn pitch he's hit. Sure it's pretty to watch his swing and the nice long arc of the ball being beautifully tracked by their 6.6 guy, but I've seen this kid hit a hard ground ball to short and beat it out.
I'm not going to argue though if my kid is on the field because he can loft a ball.
Yeah, it’s not a universally supported theory. To me it only makes sense for guys that can hit the ball out of the park. Friend of mine that is minor league hitting instructor doesn’t buy in.