While many mixed martial arts cards are held in Massachusetts every month, including regular cards at Memorial Hall in Plymouth, they are not overseen by state officials like boxing events are. Promoters more or less police themselves, hiring referees and doctors to preside over their fights. Mixed martial arts is regulated in 32 states.
“There are a lot clubs and a lot of places where they’re offering a lot of training, and they’re putting on matches,” Timilty said. “Right now it exists unfettered, unregulated. Nobody’s watching it.”
If this isn't reason enough to get MMA sanctioned by the state, then nothing is. While the organizations in the state like Mass Destruction and WCF have been good stewards, the blame they'd receive (not to mention the sport itself) if something were to compromise fighter safety would be significantly enhanced without regulation.
p.s. Some added nuances to the legalization process going on in Tennessee if you're interested.