Infamous usually trumps moderately famous, though we might not remember either one if not for the "incident".
First off, just because something is "usual" doesn't make it right or fair. Second, Nancy Kerrigan was already a rising star before the attack -- she'd won bronze at the '92 Olympics and was designated the United States Champion for the World Championships, and she had many corporate sponsorships lined up (the fact that she's gorgeous certainly didn't hurt). That's why
Harding arranged to have her attacked -- out of jealousy of her fame and success.
In fact, the attack only raised Kerrigan's profile at first, and it didn't harm her skating performance in the long run; she went on to do well at the '94 Winter Olympics. But the media decided her 15 minutes were over and tore her down because of a couple of ill-chosen comments she made while mikes were on, because the media love scandals even when they have to make them up.