Ground ***** back to the pitcher

Runner at third base, less than two outs, the infield is playing in. Why in the hell would the runner on third try to score on a ground ball back to the pitcher. It's always made my blood boil, but last game I had guys at second and third with no outs. Then back to back ground ***** to the pitcher who throws my guy out at home. Tie game in extra innings to really rub it in. F you glu.