Because maybe not enough people have reported your problem/error. This is not done by Apple, but rather by the 3rd party maps suplier.
Some people in the US have also reorted errors and they still have not been fixed. If an error is in New York on 5th Avenue and 100 people report it every day that will most likely get fixed before an error that is in the middle of the desert that 1 person reports every 6 months. It's a matter of priorities.
You will just have to wait.