Under the context of modern life, I agree. I think that the model of feudal Japan (as well as other historic Asian nations) can still hold true, but in the increasingly westernized world, it is less practical, most definitely not a requirement in most places, and much more difficult. Nowadays, yes, most of martial ways will simply never reach the pinnacle of spiritual achievement, and thus, should be considered 'less peaceful.'
However, as much as I dislike it, the human race is one of violence; "To secure peace is to prepare for war." This makes the other [mentioned] path to peace one of almost the same difficulty if one is to subject themselves to the confines of society. I, for one, would like to find a practical way to integrate the societal detachment and solitude that I think is very much a necessary part of finding peace these days with the more substinance rewarding ways of society (ie, be a hermit with a job and not have to farm all my own damn food
If that could be achieved, then I think the path to peace and true defense could be more easily be attained but also catalyzed through the martial arts. I would agree with you say that the study of martial arts specifically for fighting (self defense counting as well) would not get you there, but martial arts, as you mentioned, in the tradition of Buddhist monks to conquer one's self would. It is a concept that can easily be misinterpreted if not specifically spelled out, but given the right intention refutes part of the original arguement.
I hope this discussion can continue and go forward, if only because I enjoy the questions it forces me to ask myself, as well as stimulating my response by having to comunicate it through my fingers
. Domo arigatou gozaimashita.