Tai chi is often imitated by people who like the idea of tai chi.
Dancers, martial artists and performers copy the appearance of the art, and sometimes even claim to be teaching it.
Many classes focus on 'form', as though form were somehow the whole of tai chi rather than just a fraction of the training.
'Form collecting' occurs when an instructor fails to understand the purpose of form.
Other classes pitch the art at old age pensioners, and ignore the martial syllabus entirely...
A simplistic perception of tai chi leads people astray.