/jp/ - Otaku Culture

So I recently started hanging out with nips on a game. Some of them, though I have no specific examples will use the Kanji form of certain words, while others not seconds later will say the same word with kana and a third will say the word with kana but use Kanji for another. They're all saying the exact same thing but use Kanji for different words. Is this a regional difference or just a difference in a person's personal grammatical ability/fucks to give?