Roger started a trend at training camp that Troy continued, as long as there was a kid waiting they stayed out and signed autographs.
That said, every player has the right to do whatever he wants to do regarding autographs and some people won't sign any because they can't sign them all. Personally, I have never understood the whole autograph thing.
Good thing I am not a celebrity for autograph hounds, with my handwriting, they wouldn't know whether to put it in their collection or try to get it filled at the pharmacy.