I guess I can understand how Craft might be irritating if he didn't play on my team. As a confirmed Yankee-hater, I found the national sob-a-thon over the impending end of Derek Jeter's career one of the most nauseating events of recent years, one that will surely be exceeded when he finally leaves the field for the last time.
There's another factor in here too, which is that the Buckeyes are, or were, consistently dominating. Craft represents continuity through the era when we were perennial national title contenders; he, Buford, and Lighty were the only key players of the era to stick around for 4 seasons. Doug Etzler ticked off a lot of the same boxes as Craft, but there wasn't much point in carrying on a burning hatred for someone that played for a bottom-feeder. Craft is unpopular first and foremost because of all those wins he's had a hand in.