You can't disrupt rotations like that midseason, and no manager with any kind of a brain is going to let his top starters work innings in the middle of the season in games that don't count. Hell, they treat them with kid gloves as it is just for the All-Star Game where they can only pitch a maximum of 3 innings.
And then there's the effect of a long layoff on everyone else who is not playing. For perhaps most position players it won't matter much. For pitchers - starters and relievers - it matters a hell of a lot.
It's a different sport. Hockey has nothing comparable.
