Yes, this is a very good observation. If you have a local website, then you want to have local related information about it. For example I wanted to create a localized version for my country (Slovenia), with adding a local search engine and google.si stats to search engine stats, and local directories. But this is hard to scale and as you note the scope becomes a big problem.

If we will go covering local search engines at some point the scope problem could be solved by offering you to choose from list of (ever growing) supported resources which you want to see in addition to general google/yahoo/alexa.