I just watched this video from a guy with a refreshing perspective on the current state of TMA, and some interesting theories as to why.
As some of you know, I have been working at making my Wing Chun 'work' for fighting(with some success) by training in MMA because I feel that somewhere along the line something was lost. What he is talking about here plays into that, so I found it particularly interesting.
In general I agree with his views.
I would like to add the following:
1) For a lot of TMA's, especially those of Asian origin, the perceived prestige & prowess of the master/shifu/sensei etc. is of paramount importance, and so is 'face' and an almost paternal type of authority. This actively discourages masters from sparring with students in order to maintain that perception/authority; as such there is rarely a true sparring component in their school.
2) Speaking for tai chi chuan / taijiquan. People who gravitate towards it tend to be older nowadays and understandably are less inclined to want to actually fight, those who are younger or more inclined to want to spar/fight would quickly find out that tai chi is a really inefficient road to that goal and inevitably correct their own misstep by taking up something like Muay Thai or BJJ instead.
3) Some TMA's, especially those lumped under the 'internal' category (including Tai chi), place much more emphasis on cultivating the proper 'body' before moving to applications, and during that long initial stage, sparring may actually be counter-productive by reinforcing 'bad habits'. As a result, a lot of such schools lose touch with the application / sparring aspect of their MA's and instead base their legitimacy purely in exercises such as push hands or chi sao.