wewwers had an article in his paper that I thought really summed up the situation here and why americans act like this.
Essentially the upper classes are cracking down on dissent more firmly, and the average person becomes afraid to say anything at all because urban social movements are constantly promoting their ideologies by virtue of their wealth and high positions, and speaking against those ideologies has big consequences. You could lose your job, etc. So many people take this nihilistic neutral stance and adopt post-irony into everything they do, so that nothing they say can be taken at face value and they can more easily avoid consequence if the people promoting urban social movements come down on them. This happens everywhere, but on 4chan it is especially prevalent because there are no consequences whatsoever for saying stuff that could destroy their lives if they spoke it anywhere else, so they revel in being edgy and actively seek to offend anyone they can, because it's something they wish they could do in real life.
It's all so tiresome.