I try to move the focus or the point of view to a slightly different angle. Germans are not all "strict and following all rules" *, it's more like many americans complain that germans are more direct in their talking and not putting every sentence they say in a wrap of cotton-wool and in a roundabout way and even around the bush. They say what they think and the other party is socially conditioned by the own culture/family/society that people have to use 1000 smooth words instead of 20 harsh words to say the same thing... well.
Then the political correctness snowflake culture plays a big role.
On the one hand people are different. They're individuals. Not everybody fits to everybody. Not everybody likes one another. We're not all the same. Some people claim that, but are we all wearing the same uniform and obeying the same big brother? Not yet. Well. Some kind of.
One the other hand there are social-cultural conditions that play a role.
Often the interpretation of the slightest sarcasm is like not taking every word with a pinch of salt.
And of course the mood - let it be the day's, the week's or the year's general mood - plays a role.
* but yeah, the "deutscher Michel" is a common stereotype and it fits to many, but not to all of us. As not every woman with green hair and nose ring is dumb. But many women with green hair and nose ring learn that a lot of them are dumb, so they stop coloring their hair to green and stop wearing nose rings. Well...