Back Squats tend to be the preferred squat by most athletes because the position is easier than a front squat. There is no pressure on the wrists and it is easier to sit nice and straight. The down side to only performing back squats is you don’t develop the upper back strength that you do with front squats.
Back Squats are used by weightlifters to develop glute and quad strength which assists particularly when taking the bar off the floor during the first phase of the lift. All squatting movement should be performed in a controlled manner to achieve best results.