All college basketball fans are different, but there is one fundamental rule when it comes to those who have a particular team they root for: You must hate the rivals. And in most cases, there's one particular player on those enemy teams who warrants additional hatred.
Those getting booed and yelled at on opposing teams usually treat such dislike as a badge of honor. They often encourage the attention because it means they're getting under the skin of their own rivals' fans. The energy that comes from such rancor fuels both sides in rivalries, and it is one of the many things that makes college basketball so great.