|"Otaku is Beautiful" indeed|
This is not the case, being an "otaku" is more about having one's life revolving around a certain interest or hobby and dedicating most of the available time and money on the topic of interest. The actual topic of fixation can be basically anything from dieting, fashion, AKB48, rape porn, AKB48 rape porn, music, model trains etc. etc. I'm not completely sure here, but I would think that being a paid professional on the subject in question kinda disqualifies you from the otaku label as it's no longer just an interest or hobby.
Basically, "otaku" is not a slur or insulting in principle, but since investing the amount of time, money and effort into a single subject is borderline obsessive it usually means that the otaku is not "normal" from most perspectives.
To help you do a quick diagnosis of someone you believe might be an otaku but you're not completely sure, I have here devised a formula for you to apply to people you suspect of being otaku:
So there you have it! Now you can investigate the people around you. Generally I have nothing against otaku's in general, but I do find these "Akiba" type of otaku extremely creepy...