At every stage in the last 20 years, the leadership of the Big XII has been content to slowly cede ground to other conferences and to their own big brands within - they've been so worried about Texas leaving that their paralysis eventually led to Texas' departure. Their only proactive actions have been grifty and mean-spirited, transparent attempts to extract value by underhanded methods. Their brand has little value retained value, and no one but the unwanted schools will be sorry to see them go.
20 years ago, the Big XII had as many big names as any other football conference. They had Nebraska, A&M, Oklahoma, and Texas, the biggest program in the country. It's been a long, long fall from grace.