I agree that Mikko pretty much covers why Noise is appealing to most of us. I would add just a few other things. Most music, especially music with words, is limiting and usually has a small scope of interpretation/apprehension. Noise on the other hand is pure to me, pure sound that seems to ignore that hurdle which most mainstream music creates. Sound is more universal than words and Noise, for me, is one of the best expressions of that pure sound. The feelings that Noise can evoke are almost never as direct as the lyrically/melody driven messages in pop music and even stuff like Drone or Classical which you can usually tell that a track is suppose to be "dark" or one that is "happy". Where traditional genres usually offer diliberate and consciously available narratives, Noise brings more complex, subtle ideas and narratives to the table, ideas that don't necessarily develop in a linear way.
Noise is not marketable, therefore the majority of the "music" is made for the sake of the "music", or whatever you wish to call it. Because Noise is not marketable it is obviously viewed as unorthodox and individualistic so association with the genre also provides a sense of community and because it is so underground it is a close knit community where the people you listen to you can actually talk with about their influences, what they use to create their sounds, etc.
Atmosphere. I don't think I need to go into details about this.
The themes of most Power Electronics and Noise releases appeal greatly to me, it is a composition of everything I enjoy and am interested in (sex/porn, war, violence, etc).