You make some very good points. People who didn't see the game in the 50's or 60's just don't understand how different the game has become. Mantle was brute of a guy, but if you watched film of Yankee games back when he played you would see that Mantle didn't dig in like today's hitters. He swung harder than anyone and he would corkscrew himself into the ground on a swing and miss, but he was light on his feet in the box. They all were on their toes in the batters box. They had to be or the pitch would come under their chins.
One day a few years ago, I was listening to that Bozo, Chris Mad Dog Russo criticize the quality of play he had observed watching a film of the '52 World Series. He said that the defense was not that crisp and that even the star players bailed out on breaking pitchers. I called his show and mentioned that the infields were real dirt back then, not the multi million dollar composite material in today's infields. They actually had an occasional pebble. Those infields were not tended to by PHD's. The fielder's also had smaller gloves. As to the bailing out comment, I had to remind him that they were playing day games and they weren't wearing helmets. They stayed on their toes mindful that they could get one off the old noggin if they had dug in.
Today's players don't know how to get out of the way of a pitch. Those old timers knew how to avoid getting hit. Yaz swung as hard as anyone, but a pitcher couldn't hit him in the head. He said that he would move his head forward and duck under a pitch that was thrown behind his ear. Today's players dive into the pitch so early that they can't get out of the way if the pitch is thrown at them.