I'm sad that he has finished his career in the way he has, but I don't think it's tragic or unrepresentative. Too often footballers are canonised after their retirement, and only the good that they do is remembered. With Zidane there was much, so much, that was good. But there was always a dark side to him as well; he has a violent side to his personality which too often found its expression on the football field.
Any recollection of Zidane will no doubt rightly focus on the talent he had, and the great gaols he scored and created. But now, no epitaph to Zizou can ignore that dark side, and I think that is probably appropriate as well.