You certainly didn’t win any arguments with those claims.
0-100f is not anywhere close to the scale people see in the weather anywhere most people live. Taking where I’ve ever lived as an example:
Melbourne ~ 30-120 f vs 0-45c,
Gladstone QLD ~40-120f vs 5-45c,
Pilbara ~65-130f vs 15c-50c,
Dubai ~55-120f vs 20c-45c,
Houston TX ~ 30-120f vs 0-45c,
Pittsburg PA ~10-90 vs -15-30c.
The most iimportant number with respect to the weather is freezing, it’s handy knowing if you’re dealing with ice. The standard range for where people live is not -40 degrees, something like 2/3 of the world live between the tropics and will never see freezing or below. The -40 number makes sense if you live in Alaska or Siberia and maybe even somewhere like Minnesota, but certainly not to someone in India or Indonesia…
Neither scale is relative to cooking (which isequally arbitrary for both), though metric is easier for things like brewing 80°C tea since you need 4/5th a cup boiling water and 1/5 a cup and no thermometer.
The “feel” of the weather is hugely impacted by humidity which is why every forecast has a “feels like” measure and why 90°f in Dubai is lovely but 90°f in Houston is miserable. The increments of 10f doesn’t make sense at all, though seems to be a common perception among people who prefer fahrenheit
The comment about farenheit being more granular would be true in an alternative universe where decimals don’t exist, but not in this one.
Americans literally like farenheit more because it’s familiar, any other rationalisation is nonsense. Both measures make perfect sense after you’ve taken the time to learn them and use them daily (I know this firsthand).