That is true for law enforcement, corps and nation states perhaps, but the threat vector here is just regular people who want to track someone. They're not as saavy and don't (usually) have access to the corp/leo/government databases of locating data.

For me it's about car theft, so all I am defending against is what thiefs have access to. If I can detect a scanner popped on a car at a car show before heading back to storage, I am at a huge advantage.