To get right to the point, not all people that cut themselves are sub-human emo trash. The thing is that there is a wide variety of reasons for engaging in this practice. For some, it is a coping mechanism. Obviously, they have been psychologically damaged and this is one of the only methods by which they are able to relieve stress of grief. Others use it as a means to punish themselves for something. Again, this goes back to a mental defect. Some people are simply masochistic and they enjoy the pain or even the sight of their own blood. In certain cases, it can actually be a combination of several factors. Whatever the reason, I am of the opinion that it should be a private activity. If you are miserable and the idea of shredding your flesh with a razor or a shard of broken glass seems appealing and you feel that it will take the edge off or help your mood, go for it. Just keep it to yourself. The problem is, there are also a lot of those who do such a thing merely for the attention that they can gain by doing so.
It is a sign of the pathetic culture that we live in, today, that people would rather go out of their way to garner sympathy or concern rather than spend a few moments to come up with something interesting to say. Of course, in the age of the internet, there are many more channels by which to exploit oneself as an attention whore. Surely, there are a lot of reasons behind it. As previously mentioned, some may have no other way to feel that anyone cares for them, other than slicing their wrist and making sure someone can see it so they receive that all-important sympathy. Others may be trying to emulate some of their favourite musicians, by doing this, or attempting to seem “extreme” to those who view their wounds or scars. Naturally, these days, it is very simple to spread this around. It is common to see the typical goth-girl-turned-black-metaller who has an online profile that is filled with dozens of photos of her scarred or bleeding flesh. What is the purpose of this? Attention, of course. Perhaps, too many people admired the cover of the Abyssic Hate L.P. or the countless other sheep that got the idea that you are not “grim or cult” unless you have taken a knife to your arms and legs and made little street maps up and down them. It is my belief that the number of truly disturbed people is far less than the legion of imitators. For every person such as Per Yngve Ohlin who was genuinely melancholic, there are a dozen posers like Niklas Kvarforth who wish only to gain as much attention as possible. Based on the incessant need to display their mutilated flesh to any stranger that happens upon their internet profile, it is quite clear that most of these people are demented attention whores.
To reiterate an earlier point, if someone honestly feels that they must tear their flesh open and watch the blood come pouring forth, that's fine. But there is a difference between someone who does such a thing in private and the type of person that does so only so that others will take notice. Anyone who is slicing themselves to pieces and posting the photos online for the world to see is desperately and pathetically begging for any and all possible attention. Whether they desire the “credibility” gained by proving how little they care for their personal well-being or if they are after the sympathy that might come from those who would be concerned for them, it is all disingenuous behaviour that has no place within the black metal scene.
Such an attitude does not deserve to be associated with black metal. Exposing one's weakness for all to see – strangers, no less – seems to completely contradict what black metal was intended to stand for. While it may mean different things to different people, to take it so far from its core beliefs is to bastardize it beyond recognition. And this leads to what we have today, an ever-growing mass of gothic-emo weaklings that have hijacked black metal aesthetics and even some musical techniques, in order to cloak their whining, attention-seeking trash as something more extreme and rebellious than it really is. The entire concept of seeking attention for its own sake goes better with some other form of music.