For various reasons not many contemporary practitioners are able to realise or transmit the true method and essence of Taijiquan. The past generations of pursuants of the art valued their heritage and guarded it fiercely and did not easily pass it to another person.
Taijiquan is the essence of classical martial arts. That it had been preserved through the ages was due to the fact that it was not given over or taken up casually. If transmission had been indiscriminate it... would have long become watered down. Also, a complex art such as this can only be grasped by people who are pure in their pursuit and dedicated in their scholarship and self-cultivation.
People of superficial knowledge expect quick success. The deeper content is beyond their understanding and therefore the need to put in great efforts. They are deemed not worthy of carrying such a weighty thing.