Most will agree an Instructor’s credibility is largely based on experience and ability to teach. So it is important for an Instructor to maintain focus on what the martial arts are all about and get the best education. This means stepping out of the circle and picking up new skills, from scratch if necessary. 'Who's got got time to put certificates on the wall, I'm too busy training on the floor (John Will)'.
To be a good Instructor he or she needs to constantly update and acquire new skills so they can pass onto students. Some Instructors will also dedicate themselves to other arts and pick up a certificate along the way. In Brazilian Jiu Jitsu all you get is a belt and handshake (sometimes not even that) but it is the promotion which makes it exciting. I always say the longer between the grades (in a system), the bigger the excitement when you get promoted. I have been given Black Belt certificates in systems I have never trained in. When asked, by one guy, what did I do with it, I said, 'it's in my wallet'. I won't give you detail but you can guess the response. A certificate only means something by whom given and what for.
Whilst the world needs specialists most people, today, need to indulge in other areas because of the multi-skilling demands of society. But that should not detract from anyone wanting to train in the one system, however, the Instructor or their school should be able to provide other opportunities.
Certificates and trophies are our pride and joy, and to everyone around us, but my philosophy is 'the floor is more important than the wall'.