In 1986, Rick Schu tried unsuccessfully to bring the "ripped jeans" look into baseball. It didn't catch on.
Seriously, though, what happens when ballplayers rip their pants sliding (as was presumably the case with Schu)? Do they just patch it up or do they get a whole new uniform? I've never noticed a patched uniform but it would be expensive to replace one each time they ripped. Mark Gubicza, who had a pitching motion in which his knee scraped the dirt, would have gone through 35 pants a year if that were the case.