The following are reasons why 40% turnover per year is bad for the sport, which was the statement to which you responded. Mind you these reasons have been expressed before, but I guess you missed them.
1. 40% turnover per year means a harder time to build team chemistry = less pleasing product to watch from many teams. We happen to have a coach that can still excel in this climate, but you are looking for reasons that are bad for the sport, not bad for UConn. A less pleasing product to watch may not be an issue for fans of a few, but will be for fans of the many, hence, bad for the sport.
2. Team chemistry is what allows well-coached mid majors to catch up with more talented but less well coached majors by the time of March Madness. As one-and-dones proliferated on the college scene, so did Cinderella stories at the end of the year. With a 40% turnover hurting mid majors more than majors, we are at the beginning of an era in which we are witnessing that trend being reversed. You can count on it. Once again, good for a few, including UConn, but bad for fans of the many, hence, bad for engaging the total fanbase for the sport.
3. Fans enjoy rooting for players over time. Granted, if a one or two year player makes the kind of difference as a Cam Spenser, this does a lot towards enjoying his presence on the team for only one year. But this kind of fan enjoyment from transients will, once again, only benefit the fans of a few teams. Good for UConn, but bad for the sport.