Weeaboos.
Now, hold on.
SO!
Now that we've cleared up what they are, let's move on to the arguments and evidence against them.
1. Anime becomes off limits.
2. The use of intermittent Japanese is cringeworthy.
3. Weeaboos that actually speak Japanese might be worse...
4. They make Japanese majors/minors look bad.
5. Social media and the internet is not safe.
6. Cosplayers get pigeon-holed.
7. They present themselves like this.
8. And this...
9. Seriously?
10. Please stop.
11. I'm begging.
12. And people like this do exist.
Endnote:
While Japan has cool things to offer culturally and cool stuff to like, DON'T be a weeaboo and ruin it for the rest of us by taking it way too far. You're honestly just making yourself look strange.