Their point was related to outside temperatures, which is what most people use temperatures for. And although I've never used Fahrenheit for anything, I don't think the 100c = boiling water is useful in day-to-day life.

I've used temperatures in the 60 something to 80 something range to measure the inside of food, my oven goes anywhere from 160 to 220 degrees, but water boils when it goes all bubbly. I know that that's at 100 degrees, but I don't do anything with that info.

I don't agree with bmitc's point that Fahrenheit feels more natural. But it seems like that anytime someone has something positive to say about Fahrenheit or imperial measurement, 10 different people need to tell them how wrong they are, and how there can't be anything positive about those systems of measurement. That doesn't seem necessary to me. Especially with temperatures where everyone just remembers a couple of numbers and associates them to a certain feeling or application, and whatever you've used your entire life will feel better or more natural.

Likewise anytime anybody says that Celsius feels natural as well, you also have 10 people tell them that they are wrong and Fahrenheit is a much better fit for human beings.

Now I think these discussions often go about cherry picking examples and just limit the discussion to outside temperatures is such a cherry picking.

The real power of the metric system comes from going all-in. You can't use everything but the temperature scale. If you would do that it would be even more obvious how disconnected the temperature scale is to the whole system.

Yeah, having metric everything makes it easy to do conversions and correlating with different properties of matter, you're using the language of science (and most of the world), with proper definitions in terms of reality: atoms (for kg), distance in terms of c*some_time, volume related to mass (1ml of water => 1g of water, you can get very precise with temperature as an input). Having a standard for orders of magnitude that's consistent (micro, milli, kilo, mega, giga) is just the cherry on top.

I use the knowledge of the temperature of boiling water to calculate "how much boiling water I need to add to a water in room temperature to have my prefect tea brewing temperature".