A fighter does promos, interviews, press conferencing, and such to promote their fight. This publicity makes money for the company and fighter by bringing attention to their event. By doing these promotional and contractual obligations the fighter is really also helping raise his stock and overall pay. Why the hell would a fighter be dumb enough to forgo doing these when it's their paycheck that is directly affected? Also, if a fighter puts themselves at odds with their company/bosses it can be detrimental in the future. If someone like Conor keeps winning he's got the power, but if he has even 1 loss, it could cost him.