I have very strong feelings towards this subject, Karate instructors or Martial arts instructors in general have a MASSIVE responsibility upon their shoulders, but some do not take this responsibility anywhere near as seriously as they should.
Karate or martial arts instructors are in a very strong position of influence, the kids look up to their Sensei or teacher, they want to reach the coveted Black Belt and in some cases will do anything the Sensei or instructor says.
When I was competing I saw many Sensei or instructors, from different karate Dojo and martial art schools, some were fantastic role models, but unfortunately there were an awful lot of instructors that made the evil karate instructor from the movie ‘Karate Kid’ look like a saint! Oh, and guess what, their senior students were just the same as them.