This is a hot topic in the Capoeira circles. Since we know that Capoeira is this free art form and everyone (mestre/group) has their own agenda on how to interpret the art and on how they manage their groups/organizations it is difficult too find a general consensus of what the role of a "mestre" really is.
Each group has their criteria, their own set of requirements for someone to become a "mestre" and it can get complicate sometimes. Some groups focus on the technical abilities and/or athleticism of their students and they graduate them very quickly. Other groups may prolong the process requiring that a student understands more about Capoeira history, its "fundamento", its music, visit other rodas, schools, participate in events, organize events, etc. They believe that in order to become a "mestre" a student needs time (years) in the art. But how many years?
Imagine someone going to college for a degree in psychology, law, or engineering. The college student knows how long it is going to take to graduate. He or she will plan for their careers and in most cases have a better perspective of what is going to be like when they graduate.
One of my points here is that in Capoeira is impossible to regulate it and treat it as profession. There is not an official government department that establishes who can graduate "mestre" or not. As I have mentioned before each group has their own set to qualify someone to the title of "mestre". Sometimes one group will not recognized a master from another group because they think that that master doesn't know enough Capoeira to have this high title, or maybe he/she is too young to have the title of a master in the art.
Some groups graduate their masters too soon, others take a long time, over twenty years sometimes. So where is the common ground? "Mestre" is such a strong title. Why not graduate professors? Establish that after x years of practice and acquisition of skills one is qualified to be a teacher/professor.
Capoeira is a free art. A multidimensional art. It started that way. Anyone can create a Capoeira group anytime, anywhere and establish their own rules and requirements. Nobody can stop that. There are leagues, international organizations, federations and mega groups that in many ways want to have some kind of control over the art and its followers. I believe this is a mistake. Some of the arguments these organizers present is that by organizing the art in the same models of corporations they will "help" Capoeira. How? Capoeira doesn't need "help"! The unprepared Capoeira practitioner who wants to be a professional of the art, teach, represent and profit from it (the product) it is the one who needs help.
They need to have a set of principles that goes beyond the crafting of a kick, acrobatics or fighting skills. They need to have ethics, respect, maturity, kindness and awareness of their position as people who will be leading others. They need courses in professional development. They need to master their insecurities, their own emotional balance before they venture into teaching and guiding others.
Without these requirements anyone in any profession will be a failure and a burden to society and their communities.