Only because race has a history of
irrational prejudice and discrimination. And because race shouldn't really be predictive of anything, or at least that's the politically accepted belief. So it's been made illegal to take that into account. Which is fine, if it was just limited to that. But it's led to hundreds of other categories also being "protected", and now they are outlawing categorizing people at all. It's ridiculous.
I'm perfectly fine with Asian drivers getting cheaper insurance, if they really are somehow safer drivers. Why should they pay more, if they aren't more risky?
What about wooden buildings getting higher insurance rates? Wooden buildings are more likely to be damaged in natural disasters, burn down, suffer water damage, etc. But that's not the fault of the owner. Any specific owner could take really good care of their building, have sprinklers and alarms, maintain everything to perfect condition, etc. Yet they still pay the higher rate, so it's not a fair system. But as a group, wooden buildings are just less safe.
An older person is probably going to pay much more in life insurance than a young person. Or an overweight person, or a smoker. It may not be fair on an individual level. After all not every smoker gets cancer, not every overweight person gets diabetes, etc. But as a group, some groups have more risk than others.
The point of insurance is to predict risk as accurately as possible. Using whatever information is available. If we had time machines, we could go into the future and see what people would get into car accidents and take away their licenses. Or tear down buildings that are going to fall down and hurt people. But because we don't have that information, insurance acts as a way to hedge risk. There is zero benefit to society by making their predictions less accurate, and perhaps serious economic costs.