I have a slightly different take on what the OP Posted
I think it is specifically about those who claim to be something they are not based on certs that for all intents and purposes that they bought. They are misrepresenting themselves based on a meaningless certificate they got from a non-reputable source. And there is no way for many new students to know this and if they stay it simply adds to the destruction of the style. This is, IMO, robbing the student.
There are, most unfortunately, those who trained hard in a specific style and got all the belts and worked there way up but they simply do not get it, but they have been awarded belts based on their year long contracts and time in school.... but most certainly not on their level of skill.
Or the head teacher is rather skilled, but no longer wishes to teach, so he promotes some of his students to teach, but those students are sub-par....saw this in a Hapkido school once and it was rather sad to see. The head instructor had an impressive background and was awarded his rather high rank in Korea, but the student that were learning form his senior student had no idea how to throw a proper kick. The head instructor just sat and watched, and collected the checks
There are teacher who are great marital artists, but horrible teachers
There are teacher who are highly skilled and well trained but age is catching up with them. In this case what matters it the skill and knowledge they have that they pass on to others.
There are also good teachers that train their students well.