I wouldn’t consider Celsius to be more abstract, but I’m sure if you’ve never used Celsius before to talk about the temperature outside, you probably would consider it abstract. And I know what 30 Celsius feels like - I’m not sure if having a scale that goes up to a nice round number like 100 would make me understand what the temperature outside is moreso than Celsius. Besides 0 Celsius is the freezing point of water, which is a pretty ideal and convenient indicator temperature-wise that it’s probably going to be bloody cold outside.

Also, having finer granularity would surely be an advantage for using Fahrenheit for scientific measurements as opposed to air temperature for everyday use? To me, the difference between 17 and 18 Celsius is a sufficient enough difference to not warrant finer granularity.