The effects on a person's well being is not just physical improvements in skill. Our ability to enable a student to handle stress cannot be downplayed.
Here is a graphic example of the value of our work:
I worked in a primary school yesterday and saw the end result of suicide. There was a 5 year old boy in one class who was clearly struggling with anger issues and inability to regulate his feelings. He would strike out in anger every 10 to 20 minutes ... for the whole day.
This had been going on for two years - since he was three - when he saw his father die by suicide.
The teacher was beside herself trying to help this boy. He had 4 siblings who were also dealing with this in their own way and the mother - who I met later that day - was also dealing with immense pressure.
In our work as martial arts instructors, we help people deal with pressure. Yeah sure it is physical pressure - someone trying to hurt us - but it is the inability to deal with psychological pressure that grinds us down day after day. Until in the end, we suffer from depression, heart disease or a number of illnesses that come from suffering.
So, if we commit to helping people relax during stressful times, we help them in a way that far outreaches self defence.
It just depends how you look at it.