Because it is a real "no-no" to raise a hand to an umpire in Baseball, kicking dirt on their shoes helps them get their frustrations out and show contempt for the umps call.
They don't necessarily kick it on the feces. When dogs kick up grass or dirt,they are marking it as their "territory".
kick sand at the umpire
The ball gets handed to the umpire once it hits the dirt and not in the instance of the baseball hitting the dirt in the field is up to the Home Plate Umpire's discretion however Pitchers have the rights to request a new baseball provided it becomes too dirty to get a grip on. Pitchers will like the dirt on the ball because it will be able to move more however the opposing team and Umpires will find this an unfair advantage which is the reason in which baseballs will usually be tossed out of play to the umpire but it doesn't always happen in the event of a batted ball hitting the infield dirt.
"Footloose" by Kenny Loggins - "... kick off your Sunday shoes..."
it is broken
With the foot, in a side-sweeping motion.
Most dirtbikes are kickstart, where you kick down on a lever.
To wipe his feet! lol 8)
yes it is
Athletes shoes often have cleats on them to improve grip in dirt or grassy feilds.