ball joint covers torn, what does it cause if not fixed

my theory is they get torn from the elements and or soil conditions ... wet from the weather then dry some , also if you take your vehicle to an oil change facility some them boy's will blow the rubber boots up to a point where dirt will actually have access to the metal under it totally defeating the purpose of the rubber that retains the grease and protects the ball joints. With that being said the ball joints are subject to premature and extensive wear with out the rubber.