Yep. Interesting.
During three tours in Germany, I found just the opposite.
Of course, the folks in the big cities are like big city folks anywhere. The Germans I met, lived with, and became lifelong friends with were "country" folks- farmers from the Eifel region. They took a certain amount of pride in taking care of "their" Americans- the soldiers that they rented apartments or houses to. Almost all of us were invited to Christmas celebrations, or at least given sweets and treats by our hosts. We were welcomed at fests, and community dances. I was always welcomed at the local Gasthaus, and the men there took a particular interest in teaching me German words and phrases.
I have lived among Americans for most of my 54 years, and can probably match your stories of "plain out abject cruelty" 10 to 1.
I submit, as Exhibit A, the recent burning alive of a lady in an elevator in NYC.
Since we are discussing stories of people we have "lived among... what ya got?
Maybe the trick is drinking with them at the gasthaus. Maybe your experience was closer to the post war era when they were still appreciative of Americans and our sacrifices. My experience was pretty recent. I stand by my observations. Additionally, Germans are pretty well loathed through out Europe because of their rudeness, coldness, lack of humor, etc.