I think it's a case of brand recognition now - which is why it hasn't been changed
A few years back up here in Ontario, there was a big brouhaha about a name change one of the townships were considering. Seems there was a road called N-i-g-g-e-r trail (without the hyphens) that white officials in the township wanted to change. They felt the name was racist, and were embarassed about having a road in their township with that name. The Black History Society fought the name change tooth & nail. I think it was designated a Heritage Site. It was originally given that name over 150 years ago, because it was the road many American Blacks used on the Underground Railroad when escaping slavery in the US for a life of freedom in Canada.