I have seen a lot of Americans say this, which just doesn't make sense.
Celsius and Fahrenheit , or even Kelvin, are just different measure units, which has nothing to do with accuracy.
Celsius devides freezing point/boilling point difference into 100 degree, which is just easier to comprehend.
If you want accuracy, you can go 23.13479438574398 C, which is more accurate than 123.001 F.