I think this is one of these headlines that miss the point:
"Kasparov criticised as sore loser after Op-Ed on Deep Blue (Op-Ed)"

Of course he's a sore loser. How do you think he got to be one of the three or four best chess players in the history? By liking to lose? By taking it easily? Of course he's a sore loser, and all the more so because he was robbed of the only revenge you can get in that world, another chance at his opponent.

Of course, chess has a long history of champions refusing to replay their top opponents. Look at Alekhine and Capablanca.