And what about the ability to take pain? Also, practicing hard/fast can sometimes involve pain (again: not because of injury but rather because of general muscle aches, etc, due to exhaustion and feeling "battered")? Do you think one should practice to the point of experiencing a certain amount of pain? Always? Never? Just playing devilīs advocate here
Pain is an interesting subject!
pain is inherent in life. In an ideal situation we would not experience pain at all! Unfortunately we all know that is not the case. Interesting is that buddhism is really centered around reducing or removing suffering in life (pain). Anyway, you are talking about physical pain, but I think they are related as pain is really about perception of cause and effect!
So, I think pain can be important in martial arts as it gives us experiences upon which to learn. We can develop skills to reduce it, resolve it, or reframe it. Ignoring pain, IMO, is not the answer. To me this equates philosophically to ignoring conflict. It doesn't go away...it just festers. Ignoring physical pain, or "being tough" doesn't do anything either other than cause further damage. It may mean a torn muscle or ligament...or it may cause emotional damage as well!
So, we must recognize pain, accept it, embrace it, use it as a tool to develop our skills. That, however, is not the same thing as causing pain, or "sucking it up", or "toughing it out".