The argument goes that they should take advantage of their status by sending positive messages to the public. Others will argue the opposite. People like Charles Barkley will say that athletes should not be role models, parents should. They have the most direct contact with their own kids, so they should be the role model. The way I see it, both arguments are right.
Parents are, in fact the first person that their children look up to.
As a father of two myself, I am always aware of what I say and do in front of them. I know that they are like sponges. This does not absolve athletes. They, have the same responsibilities as a parent, or teacher to show those after them a positive example. We as teachers want to use as many means as possible to reach our students.