Baseball fields- Warning track in foul territory- why not dirt?

After watching J. T. Snow fail to make a play because of Dodger Stadium’s rubberized warning track by the visitor’s dugout, I have to wonder why the entire warning track isn’t dirt, like it is in the outfield.

Typical track dirt is certainly of a different enough texture than the grass to be noticeable to players, though I will concede that the rubberized track is even more different than grass.

An all-dirt track would allow for easier play, since the rubber doesn’t allow for sliding or diving. Can baseball spikes even get a hold in the rubber?

WAG, if the track is rubberized by the dugouts, maybe it allows the players to remove field dirt from their cleats more efficiently, keeping the dugout from becoming a repository for clumps of dirt? Just brainstorming…