Learning any instrument offers many positives. The most timid of students can come alive in performance, displaying an inner confidence that they may not have known they had: the ability to be self-critical allows a student to identify issues and focus in on problems effectively and furthermore; learning an instrument can teach the virtue of patience with working and playing alongside other musicians with different strengths.
Teaching an instrument should not start and finish at showing someone how to play an instrument. There is so much depth and breadth within the art of music that it is such a shame to leave a student with ability rather than an understanding.
I have found it a problem that guitarists, who often work with drummers, never sit down behind a drum kit and see what issues drummers have; so I teach guitarists basic drums. Drummers can often allow entire music conversations to pass them by because their instrument revolves around rhythm and not melody; I teach drummers basic piano skills. All this creates a musical understanding that can be left behind in the pursuit of being faster, louder or at a higher grade.
Although my musical education was through examination, I find great worth in experimentation through improvisation and composition. I do find examination exceptionally valuable and advisable, however a student can get to know their instrument through immersing themselves into composition and improvisation, allowing creativity and imagination to develop through their studies.