How many people train their internal art correctly?

Although tai chi is widely practiced and popular, not many students are learning tai chi chuan: the martial art.
Most students are training tai chi for health, or as a performance art.

Very few people are engaged in learning the internal arts properly.
Some combat tai chi people externalise the art in order to make it easier to learn. 
But this does not succeed.
Instead, it creates a new art: an external hybrid based upon the idea of tai chi.

Training an internal art correctly - using the principles of the art fully and faithfully - is relatively rare these days.
It requires a lot of hard work, exploration, study, patience and practice.