Why do people like this pairing?

Swift says: "In Sonic X, it was Chris who reminded Shadow of Maria, not Amy. It's that heart-warming resemblance to her that made him save Chris from Prison Island. If he truly didn't care, he'd have left him there to die. And it was Chris in Sonic X, not Amy, who reminded Shadow of Maria's true promise. No matter how hard Shadow beat him or how much Shadow denied what Chris was saying, Chris never gave up, because he knew there was a really nice, caring, emotionally confused guy in Shadow underneath all the cold, pained anger he put on as a front. Chris was also the one from Blue Typhoon who was probably the most shocked to see Shadow alive and he was the one who kept his ring in Sonic X, not Rouge."