I have no problem believing that Americans find the Fahrenheit system intuitive, but you are failing to see that for metric users, Celsius is 100% intuitive. I know exactly what sort of clothes to wear for each gradation (assuming it's not something insane like -60C in which case I'm staying home anyway), whereas I genuinely cannot do the same calculus with just Fahrenheit, even taking into account the 0-100 concept of Fahrenheit, which is in itself busted in various regions from Canada to Saudi Arabia. I have to constantly remind myself of what Fahrenheit means, because I never grew up with it.
For metric users, Celsius is 100% familiar. Intuitive means that there are a bunch of hints that can give you an idea of values that you don't know. The fact that 0° Fahrenheit is about as cold as you can easily stand and 100° Fahrenheit is about as hot as you can easily stand is something that gives you an intuition: if it's as hot as I can stand, it's about 100°, if it's as cold as I can possibly stand, it's about 0°. I can figure out intermediate values through converting my feelings into a percentage.
You can of course do that with Celsius too, but Celsius hasn't been built around a range of human feeling, it's been built around the phase changes of water. You just have to remember the human comfort range in Celsius, do all the same calculations as above, multiply the result by the difference between your low human range and your high human range, then add that to your low human range to get an answer. There's no help, and it might as well be arbitrary.
This is a post-facto rationalization for two reasons.
The first is that the Fahrenheit scale wasn't built around a range of human feeling, but originally around a substance whose temperature is easy to stabilize. Following this, the human temperature was set at 96 (later adapted to 98.6) and the melting point of ice at 32 to have 64 gradations to help with measurements linked to specific hardware. If it was designed around human feeling, then 98.6 and the freezing temperature of brine is hardly helpful.
The second is that if it were intuitive on its own, people who don't use the system regularly would still be able to remember the logic, but that's not what typically happens. Every time I need to think in Fahrenheit (which tends to only be online debates about this very topic), I can't picture anything clearly even with the purported 0 to 100 concept. It is a subjective appraisal of temperature that can't help me convert feelings into anything useful because the limits are still arbitrary. If -17.7C is the lowest a person can possibly stand, then Canadians are gonna be iced out. If 37.7C is the highest a person can possibly stand, Saudis are cooked. The number of regions that hold a range that's appreciably close to that 0 to 100 is quite small.
> The first is that the Fahrenheit scale wasn't built around a range of human feeling
How and why Fahrenheit was developed is completely immaterial: what is material is whether and how its range is of value to its users now.
> Every time I need to think in Fahrenheit (which tends to only be online debates about this very topic), I can't picture anything clearly even with the purported 0 to 100 concept.
Your argument is "because I'm not used to Fahrenheit, it must not offer an advantage to people used to it"? Really? C'mon.
This is a theory of mind issue.