It's not so much that they don't like you, but given it's only spoken in their country, the Japanese are quite protective of their language. If you can show them you can understand them (which is difficult without using 3rd party tools) they become a lot more open to you.

There are some who do not like foreigners, especially people who were playing the game before it was released in other regions (because Square Enix did not ever announce its intention to do so ahead of time.) But for the most part, it's because Japanese are a private people and they keep to themselves a bit more than we do.