It's a world car shipped to markets that use C and F measurements.
Saves the need for two different dash gages.
While that may be true, I don't think that's the reason. Absolute numbers aren't important. Does anyone really care if the oil temp is 130C?! I think just a gauge with a normal and "red" zone is more than reasonable. Heck, Lamborghini doesn't localize their gauges (Benzina, Oilo, etc), yet I manage just fine.