Her grandfather played football there. I think the family was raised Tiger fans.
People were waiting to see if Clemson hired some up and coming unproven assistant from somewhere or who maybe coached at a small school (like Duke did), or a proven P5 coach. It makes perfect sense especially if you are a parent of a kid looking at their options right now, and a travel ball coach advising them. In the softball world, Clemson hired the football equivalent of Bob Stoops or Les Miles or something like that - everyone in the game knows who they are, what they have done and doesn't need to Google their name.
Not to throw down on Duke's hire (Marissa Young), but in the softball world she's unproven. Plus the admission standards are already tough enough at Duke, plus she has to convince them to come play for a new coach at a new program. IMO, Duke missed out on Rittman as someone who can win with tough admission standards (Stanford). It's not easy to win at schools like that.
At the end of the day, Clemson's program is going to battle for recruits from the GA/TN//AL/FL/SC area that has become very fertile recruiting ground in the past 5+ years or so for the SEC. I give Rittman two years before he qualifies for the NCAA tourney, and 4 years before he wins a Super Regional.