German here - drink pretty much exclusively tap water. Ordering tap water in a restaurant definitely IS frowned upon (the restaurant has to choose putting it on its menu and/or accommodate your request) , but I have yet to meet another German who would take offense at drinking Kraneberger.
I guess there may be regional differences, but it's very clearly not universal.
> There was a time before air conditioning when it was possible to heat and cool buildings.
There are a lot of old buildings with thick walls as well as special building styles (like the Fachwerk that we apparently have a lot of, compared to other countries) that deal very well with heat and, I must admit, have a much superior air quality and just overall feeling of climate than any air conditioned building I have experienced so far. Perhaps those are adjusted to a very particular temperature profile, though, and if the climate changes, AC might start to make more sense.
I don't think we have very good experience with installing AC, though. Just an anecdote, but at my $JOB, we're housed in a very "modern" building with light materials, large windows from floor to ceiling, exposure to sunlight from dawn till dusk and a hilariously impotent AC (supposedly fed by an innovative ice storage something or other). The people in charge do a marvelous job of pretending, for years now, that it's a complete mystery why the ac keeps failing to move the needle - at the record heat of 39°C outside, the temperature inside climbs well beyond 32°C. But I guess that makes sense if you were responsible for making as basic a mistake as "building the walls too thin".
> As soon as the fatties that need air-con completely take over then that is game over
Aber sag uns doch endlich mal was du wirklich von den Amerikanern hältst, Klaus-Dieter.