why are people writing 兄 without honorifics??

Step one, you master お兄さん in chapter three of Genki. Step two, you learn the kanji 兄. But today I saw just 兄 alone in a post and it threw off my entire study flow. People who skip the polite forms to look cool are ruining their foundation. You can't just jump ahead of the textbook curriculum. Why are we ignoring the proper sequence?