It brings in money to the school. It gives the school prestige. The better the players are, the more notice the school gets and that translates into more money. Athletes like Ma are special commodities and should be treated as such. Like it or not, sports isn't about obeying the rules and promoting fair play.
Sports is a business ruled by dollars and cents.
If the women's volleyball team brings the school any money, it's because of Ma. She brings people to the ticketbooth and puts asses in the seats. It's about winning and losing, nothing more. In a perfect world, Ma should be allowed to play regardless of the investigation. It's a business and, like any other business, sometimes extreme measures are needed to ensure its success.