I suppouse I should admit to the forums that I was once an Otaku myself, started when I was 13-14, and lasted till I was 16-17.
I remember the day I stopped being an Otaku clearly, I was in the central library in my city where my old man works, with my best bud, we were sitting on some chairs in a corner near a window on a second artificial raised floor with the window going down to the proper floor below. the sun was golden, probably around 3-4 pm.
I was drawing some Manga, we both were, and my mate went away for a second, I forgot which, most likely to find a toilet, and I suddenly relised that aside from making a pact with the dark gods and gaining super-human powers, I was never going to become a manga-artist in Japan and I had no real interest in becomming a "manga" artist for western audiences, mainly because at the time, as far as I was aware, Manga and western otakunism was strictly based off of Japanese source material.
I was fairly good at drawing manga aswell, and I could probably get my skills back with some practice, I already have an acceptable lower standard when I doodle, which sadly now is extremely rare.
The point is I grew out of it, with a help of some realizations, and I came to know a more real Japan, which was far more interesting anf facinating then the Otaku image, without having any obsessive symptoms around it.
My energies moved onto gaming, sci-fi, but mroe importantly, scientific study, travelling and exploring, and understanding the world better.
I wouldnt trade my experiences and memories of Japan through the eyes I witnessed it at the time for any Otaku fantasy in the world.
The real deal, and my 3 month stay there was more special and facinating to me then any anime image of it.
I think the problem is for otaku's, especially the younger variety, is that without practical experience or knowledge of Japan, they cant seperate the anime image from the real one.
Its amazing the massive difference between people in real life in Japan, and their anime counter-parts.
Anime is the one place where Japanese social pressures are weak or non-existant, it gives somewhere for Japanese people to express themselves emotionally moreso then daily life, its escapism, just like western escapist interests.
I have a hypothesis that in Japanese society, being a high pressure social enviroment for many, Anime needs to be a powerful escapist "therapy", and this has a powerful draw to teenage western otaku's, who may feel strong pressures upon them in their own lives.
Adult long term or even perminant Otakuism is somewhat different, and I'll leave it to someone who is more familiar with them to comment on that.
Most teenage otaku's will grow out of it, for the rest, meh, aslnog as they arent bothering me I wont bother them.