I will answer for myself, but I do so as a practising Mixed Martial Artist.
In theory, and generally speaking, the Martial Arts do not aim at the destruction of the opponent, and are underpinned by philosophical assumptions conducive to the Christian spirit. For example, the Art of Hapkido (one of the Martial Arts i'm being trained in) is underpinned by what is known as the 'Principle of Water' which seeks to build patience and non-resistant adaptability. When water flows down a hill, for example, towards a rock, it doesn't seek to push past the rock by exerting extra force, rather it just flows around it (harmonious adaptability); should the rock be too large to allow the stream of water to pass around it, the water patiently waits until it reaches sufficient volume on the rock to overflow that rock. Such is the type of psychology that Hapkido techniques instil in the practitioner, and no doubt this can be spiritualised in a number of meaningful ways. More generally, most of the Martial Arts help develop a Christian character by inspiring humility, patience, perseverance, focus, discipline, and respect. Mixed Martial Arts, incorporating the techniques of a variety of Martial Arts, in a sense increases the intensity of the physical and psychological conditioning involved and hence reinforces the general virtues aroused by the individual Martial Art systems to a greater degree. The spiritual implications of MMA training are, as I have discovered by experience, many, and I have plenty more examples and issues that I could discuss in further detail, but I’ll leave it at that.
In terms of viewing MMA matches, I personally don't find it enjoyable when I see two fighters simply trying to destroy each other whilst using very little technique—which I think I made pretty clear in my previous post. MMA is not about brutal force. I enjoy watching fights with a trained eye able to pick up on good methodical and technical movements and maybe even learn a few such moves myself. When we fight at our MMA gym, we are constantly taught not to exert so much force in a punch or kick as if in an attempt to knock the opponent out, but only to employ kicks and punches strategically. The fight should end not because the opponent got knocked unconscious by a power blow to the head, but because he was strategically put into submission—a point at which he is able to tap out before incurring any real injury.
I don't doubt that some enjoy watching MMA just to watch their favourite fighter beat the heck out of the opponent; and I am aware that even in my own MMA centre, some of the guys I train with couldn't give a hoot about strategy or character development, but just want to be to able to kick some butt should they ever get into a street fight. In the end, "to the pure, all things are pure".