' I didn't mean to offend - apologies if I have'

Of course not! Thanks for your comment. ;-)

There's nothing like a bit of hyperbole to get a debate started (and these days there's never enough of what I'd call formal debating going on).

I don't live in the US but I've been there many times and even worked there in a technical capacity (and most of my relatives are US citizens), so I understand where you are coming from so I understand why the US thinks the way it does about temperature measurement.

Another comment I'd make is the fact that the US's continued use of imperial measurements/standards is a significant cost to other countries that have to trade with the US. Exports from the US that are in imperial measurements cause all sorts of compatibility and maintenance problems. Similar problems occur with imports to the US that must be in imperial units; this adds considerable additional cost to manufacturing plants in many countries. Another problem is that in recent years the Chinese have borne much of the brunt of having to manufacture stuff in two standards—stuff in metric for themselves and everyone else except the US, then in imperial for the US. That's the position in theory anyway, the trouble is that the overflow from China's manufacturing for the US often flows elsewhere, so we end up here with nuts, bolts, etc, etc. that are in imperial sizes and this also causes a multitude of problems. You only have to go to one of our major hardware stores to see the problem firsthand, there's thousands of essentially identical (duplicated) items except for one lot being in imperial and the other in metric units (1/4" thread ≈6mm, etc.). This doubling up means huge price hikes because of the need to hold smaller individual quantities and extra line/inventory items not to mention all the extra shelf space. Yes, it's right damn mess because of the US!

Same goes for the US's 110-117 Volt/60 Hz power system which often sees exported equipment blowing up from over voltage on 220-240 volt 50Hz systems (or that said equipment needs 220/240-110V transformers to use them)—as much of the rest of world uses 220-240V—as we don't have the luxury of having huge copper reserves à la Bingham Canyon mine [sorry, as it once had] to waste on thick copper low-voltage busbars. I know from experience, only recently I blew up a very expensive Tektronix spectrum analyzer that was 'correctly' wired with a 220-240V plug but was still internally set for 110V. Even when US manufacturers figure out that there are other power standards from their own and they supply power transformers to suit, we often find that they've forgotten that everyone else is on 50Hz and not 60Hz, so the transformers overheat (lower frequency thus less inductive reactance)!

There's little wonder much of the world gets annoyed with American Exceptionalism.

'I still don't know what room temperature is in Celcius.'

I know this is a commonplace view in the US but I must admit it's pretty odd one for most of us outside the US (except the UK, but nevertheless they've still some notion of Celsius). I'm old enough to remember Fahrenheit. At school the first thing we did when entering the science lab was to write down barometric pressure, humidity and the temperature in both Celsius and Fahrenheit (Fahrenheit in brackets as it was the lesser important of the measurements) in our workbooks. The room temperature is also puzzling, for that one is so well known: 20°C is nominally 68°F. If you've ever done photographic processing and bought a Kodak developing thermometer—even in the US—then it had both scales on it and a big black line at this magic room temperature of 20°C. Moreover, the conversion formula was drummed into everyone until it was mantra (almost all lab equipment is calibrated at 20°C - even in the US):

T(°F) = T(°C) × 9/5 + 32

'I really don't think this was written with misleading, malicious intent'

Again, of course not! However, I'll leave the last word about such matters to your own countryman Ambrose Bierce, https://en.wikipedia.org/wiki/Ambrose_Bierce, https://quotes.yourdictionary.com/author/quote/592604 who once aptly said:

'War is God's way of teaching Americans Geography'

…A quote that's very well known outside the US!