Japanese anime lovers?

Question:

There are alot of people in countires other than Japan who love anime, like me, and it's considered okay that we like anime and can obsess over it with other anime lovers. However, apparently, if you obsess over anime and you're Japanese, you get called an Otaku which i belive means a nerd or geek. So basically it's offensive. But people in other countries call themselevs Otakus but it's not offensive, it just means you love anime. Anyway my point is, why do Japanese make anime but then get called a geek or nerd (otaku) if they love them? (sorry this question's abit all over the place and probably doesn't make sense, i was just curious, though)

Answer:

Well I don't think they'd be made fun of for having just a normal liking of Anime. However, in Japan, like many other countries I'd guess, people can take it too far. And when people take things too far, then they're generally ridiculed for it.
When it goes as far as being called an Otaku, I imagine the person being obsessed with Anime and making it their life. And I think when it goes that far, that's when it gets a little weird, and people make fun. I can't imagine it being any different in Western countries either.