Adding 7ths and 9ths certainly is changing the harmony, as is changing a diminished to a half-diminished chord (which also changes its function), so that elemen

Adding 7ths and 9ths certainly is changing the harmony, as is changing a diminished to a half-diminished chord (which also changes its function), so that element of the criticism is true and warranted. As for "fair", I think having one's (many people's!) time wasted by baiting them with a false promise, only to present them with something likely to produce confusion and frustration, is unfair.